diff --git a/src/bin/musichoard-edit.rs b/src/bin/musichoard-edit.rs
index f589b12..8d06e32 100644
--- a/src/bin/musichoard-edit.rs
+++ b/src/bin/musichoard-edit.rs
@@ -5,7 +5,7 @@ use structopt::{clap::AppSettings, StructOpt};
 use musichoard::{
     collection::{album::AlbumId, artist::ArtistId},
     database::json::{backend::JsonDatabaseFileBackend, JsonDatabase},
-    MusicHoard, MusicHoardBuilder, NoLibrary,
+    IMusicHoardDatabase, MusicHoard, MusicHoardBuilder, NoLibrary,
 };
 
 type MH = MusicHoard<JsonDatabase<JsonDatabaseFileBackend>, NoLibrary>;
diff --git a/src/core/musichoard/builder.rs b/src/core/musichoard/builder.rs
index 3a99805..0a9f53e 100644
--- a/src/core/musichoard/builder.rs
+++ b/src/core/musichoard/builder.rs
@@ -3,7 +3,7 @@ use std::collections::HashMap;
 use crate::{
     core::{
         interface::{database::IDatabase, library::ILibrary},
-        musichoard::{MusicHoard, NoDatabase, NoLibrary},
+        musichoard::{database::IMusicHoardDatabase, MusicHoard, NoDatabase, NoLibrary},
     },
     Error,
 };
diff --git a/src/core/musichoard/database.rs b/src/core/musichoard/database.rs
index 19f26e0..d9aa6c0 100644
--- a/src/core/musichoard/database.rs
+++ b/src/core/musichoard/database.rs
@@ -9,16 +9,66 @@ use crate::core::{
     musichoard::{base::IMusicHoardBasePrivate, Error, MusicHoard, NoDatabase},
 };
 
-impl<Library> MusicHoard<NoDatabase, Library> {
-    pub fn commit(&mut self) -> Result<(), Error> {
-        self.collection = self.pre_commit.clone();
-        Ok(())
-    }
+pub trait IMusicHoardDatabase {
+    fn reload_database(&mut self) -> Result<(), Error>;
+
+    fn add_artist<IntoId: Into<ArtistId>>(&mut self, artist_id: IntoId) -> Result<(), Error>;
+    fn remove_artist<Id: AsRef<ArtistId>>(&mut self, artist_id: Id) -> Result<(), Error>;
+
+    fn set_artist_sort<Id: AsRef<ArtistId>, IntoId: Into<ArtistId>>(
+        &mut self,
+        artist_id: Id,
+        artist_sort: IntoId,
+    ) -> Result<(), Error>;
+    fn clear_artist_sort<Id: AsRef<ArtistId>>(&mut self, artist_id: Id) -> Result<(), Error>;
+
+    fn set_artist_musicbrainz<Id: AsRef<ArtistId>, S: AsRef<str>>(
+        &mut self,
+        artist_id: Id,
+        url: S,
+    ) -> Result<(), Error>;
+    fn clear_artist_musicbrainz<Id: AsRef<ArtistId>>(&mut self, artist_id: Id)
+        -> Result<(), Error>;
+
+    fn add_to_artist_property<Id: AsRef<ArtistId>, S: AsRef<str> + Into<String>>(
+        &mut self,
+        artist_id: Id,
+        property: S,
+        values: Vec<S>,
+    ) -> Result<(), Error>;
+    fn remove_from_artist_property<Id: AsRef<ArtistId>, S: AsRef<str>>(
+        &mut self,
+        artist_id: Id,
+        property: S,
+        values: Vec<S>,
+    ) -> Result<(), Error>;
+    fn set_artist_property<Id: AsRef<ArtistId>, S: AsRef<str> + Into<String>>(
+        &mut self,
+        artist_id: Id,
+        property: S,
+        values: Vec<S>,
+    ) -> Result<(), Error>;
+    fn clear_artist_property<Id: AsRef<ArtistId>, S: AsRef<str>>(
+        &mut self,
+        artist_id: Id,
+        property: S,
+    ) -> Result<(), Error>;
+
+    fn set_album_seq<ArtistIdRef: AsRef<ArtistId>, AlbumIdRef: AsRef<AlbumId>>(
+        &mut self,
+        artist_id: ArtistIdRef,
+        album_id: AlbumIdRef,
+        seq: u8,
+    ) -> Result<(), Error>;
+    fn clear_album_seq<ArtistIdRef: AsRef<ArtistId>, AlbumIdRef: AsRef<AlbumId>>(
+        &mut self,
+        artist_id: ArtistIdRef,
+        album_id: AlbumIdRef,
+    ) -> Result<(), Error>;
 }
 
-impl<Database: IDatabase, Library> MusicHoard<Database, Library> {
-    /// Load the database and merge with the in-memory collection.
-    pub fn reload_database(&mut self) -> Result<(), Error> {
+impl<Database: IDatabase, Library> IMusicHoardDatabase for MusicHoard<Database, Library> {
+    fn reload_database(&mut self) -> Result<(), Error> {
         self.database_cache = self.database.load()?;
         Self::sort_albums_and_tracks(self.database_cache.iter_mut());
 
@@ -28,7 +78,146 @@ impl<Database: IDatabase, Library> MusicHoard<Database, Library> {
         Ok(())
     }
 
-    pub fn commit(&mut self) -> Result<(), Error> {
+    fn add_artist<IntoId: Into<ArtistId>>(&mut self, artist_id: IntoId) -> Result<(), Error> {
+        let artist_id: ArtistId = artist_id.into();
+
+        self.update_collection(|collection| {
+            if Self::get_artist(collection, &artist_id).is_none() {
+                collection.push(Artist::new(artist_id));
+                Self::sort_artists(collection);
+            }
+        })
+    }
+
+    fn remove_artist<Id: AsRef<ArtistId>>(&mut self, artist_id: Id) -> Result<(), Error> {
+        self.update_collection(|collection| {
+            let index_opt = collection.iter().position(|a| &a.id == artist_id.as_ref());
+            if let Some(index) = index_opt {
+                collection.remove(index);
+            }
+        })
+    }
+
+    fn set_artist_sort<Id: AsRef<ArtistId>, IntoId: Into<ArtistId>>(
+        &mut self,
+        artist_id: Id,
+        artist_sort: IntoId,
+    ) -> Result<(), Error> {
+        self.update_artist_and(
+            artist_id.as_ref(),
+            |artist| artist.set_sort_key(artist_sort),
+            |collection| Self::sort_artists(collection),
+        )
+    }
+
+    fn clear_artist_sort<Id: AsRef<ArtistId>>(&mut self, artist_id: Id) -> Result<(), Error> {
+        self.update_artist_and(
+            artist_id.as_ref(),
+            |artist| artist.clear_sort_key(),
+            |collection| Self::sort_artists(collection),
+        )
+    }
+
+    fn set_artist_musicbrainz<Id: AsRef<ArtistId>, S: AsRef<str>>(
+        &mut self,
+        artist_id: Id,
+        url: S,
+    ) -> Result<(), Error> {
+        let mb = MusicBrainzUrl::artist_from_str(url)?;
+        self.update_artist(artist_id.as_ref(), |artist| artist.set_musicbrainz_url(mb))
+    }
+
+    fn clear_artist_musicbrainz<Id: AsRef<ArtistId>>(
+        &mut self,
+        artist_id: Id,
+    ) -> Result<(), Error> {
+        self.update_artist(artist_id.as_ref(), |artist| artist.clear_musicbrainz_url())
+    }
+
+    fn add_to_artist_property<Id: AsRef<ArtistId>, S: AsRef<str> + Into<String>>(
+        &mut self,
+        artist_id: Id,
+        property: S,
+        values: Vec<S>,
+    ) -> Result<(), Error> {
+        self.update_artist(artist_id.as_ref(), |artist| {
+            artist.add_to_property(property, values)
+        })
+    }
+
+    fn remove_from_artist_property<Id: AsRef<ArtistId>, S: AsRef<str>>(
+        &mut self,
+        artist_id: Id,
+        property: S,
+        values: Vec<S>,
+    ) -> Result<(), Error> {
+        self.update_artist(artist_id.as_ref(), |artist| {
+            artist.remove_from_property(property, values)
+        })
+    }
+
+    fn set_artist_property<Id: AsRef<ArtistId>, S: AsRef<str> + Into<String>>(
+        &mut self,
+        artist_id: Id,
+        property: S,
+        values: Vec<S>,
+    ) -> Result<(), Error> {
+        self.update_artist(artist_id.as_ref(), |artist| {
+            artist.set_property(property, values)
+        })
+    }
+
+    fn clear_artist_property<Id: AsRef<ArtistId>, S: AsRef<str>>(
+        &mut self,
+        artist_id: Id,
+        property: S,
+    ) -> Result<(), Error> {
+        self.update_artist(artist_id.as_ref(), |artist| artist.clear_property(property))
+    }
+
+    fn set_album_seq<ArtistIdRef: AsRef<ArtistId>, AlbumIdRef: AsRef<AlbumId>>(
+        &mut self,
+        artist_id: ArtistIdRef,
+        album_id: AlbumIdRef,
+        seq: u8,
+    ) -> Result<(), Error> {
+        self.update_album_and(
+            artist_id.as_ref(),
+            album_id.as_ref(),
+            |album| album.set_seq(AlbumSeq(seq)),
+            |artist| artist.albums.sort_unstable(),
+            |_| {},
+        )
+    }
+
+    fn clear_album_seq<ArtistIdRef: AsRef<ArtistId>, AlbumIdRef: AsRef<AlbumId>>(
+        &mut self,
+        artist_id: ArtistIdRef,
+        album_id: AlbumIdRef,
+    ) -> Result<(), Error> {
+        self.update_album_and(
+            artist_id.as_ref(),
+            album_id.as_ref(),
+            |album| album.clear_seq(),
+            |artist| artist.albums.sort_unstable(),
+            |_| {},
+        )
+    }
+}
+
+pub trait IMusicHoardDatabasePrivate {
+    fn commit(&mut self) -> Result<(), Error>;
+}
+
+impl<Library> IMusicHoardDatabasePrivate for MusicHoard<NoDatabase, Library> {
+    fn commit(&mut self) -> Result<(), Error> {
+        self.collection = self.pre_commit.clone();
+        Ok(())
+    }
+}
+
+impl<Database: IDatabase, Library> IMusicHoardDatabasePrivate for MusicHoard<Database, Library> {
+    fn commit(&mut self) -> Result<(), Error> {
         if self.collection != self.pre_commit {
             if let Err(err) = self.database.save(&self.pre_commit) {
                 self.pre_commit = self.collection.clone();
@@ -38,7 +227,9 @@ impl<Database: IDatabase, Library> MusicHoard<Database, Library> {
         }
         Ok(())
     }
+}
 
+impl<Database: IDatabase, Library> MusicHoard<Database, Library> {
     fn update_collection<FnColl>(&mut self, fn_coll: FnColl) -> Result<(), Error>
     where
         FnColl: FnOnce(&mut Collection),
@@ -92,132 +283,6 @@ impl<Database: IDatabase, Library> MusicHoard<Database, Library> {
         fn_artist(artist);
         self.update_collection(fn_coll)
     }
-
-    pub fn add_artist<IntoId: Into<ArtistId>>(&mut self, artist_id: IntoId) -> Result<(), Error> {
-        let artist_id: ArtistId = artist_id.into();
-
-        self.update_collection(|collection| {
-            if Self::get_artist(collection, &artist_id).is_none() {
-                collection.push(Artist::new(artist_id));
-                Self::sort_artists(collection);
-            }
-        })
-    }
-
-    pub fn remove_artist<Id: AsRef<ArtistId>>(&mut self, artist_id: Id) -> Result<(), Error> {
-        self.update_collection(|collection| {
-            let index_opt = collection.iter().position(|a| &a.id == artist_id.as_ref());
-            if let Some(index) = index_opt {
-                collection.remove(index);
-            }
-        })
-    }
-
-    pub fn set_artist_sort<Id: AsRef<ArtistId>, IntoId: Into<ArtistId>>(
-        &mut self,
-        artist_id: Id,
-        artist_sort: IntoId,
-    ) -> Result<(), Error> {
-        self.update_artist_and(
-            artist_id.as_ref(),
-            |artist| artist.set_sort_key(artist_sort),
-            |collection| Self::sort_artists(collection),
-        )
-    }
-
-    pub fn clear_artist_sort<Id: AsRef<ArtistId>>(&mut self, artist_id: Id) -> Result<(), Error> {
-        self.update_artist_and(
-            artist_id.as_ref(),
-            |artist| artist.clear_sort_key(),
-            |collection| Self::sort_artists(collection),
-        )
-    }
-
-    pub fn set_artist_musicbrainz<Id: AsRef<ArtistId>, S: AsRef<str>>(
-        &mut self,
-        artist_id: Id,
-        url: S,
-    ) -> Result<(), Error> {
-        let mb = MusicBrainzUrl::artist_from_str(url)?;
-        self.update_artist(artist_id.as_ref(), |artist| artist.set_musicbrainz_url(mb))
-    }
-
-    pub fn clear_artist_musicbrainz<Id: AsRef<ArtistId>>(
-        &mut self,
-        artist_id: Id,
-    ) -> Result<(), Error> {
-        self.update_artist(artist_id.as_ref(), |artist| artist.clear_musicbrainz_url())
-    }
-
-    pub fn add_to_artist_property<Id: AsRef<ArtistId>, S: AsRef<str> + Into<String>>(
-        &mut self,
-        artist_id: Id,
-        property: S,
-        values: Vec<S>,
-    ) -> Result<(), Error> {
-        self.update_artist(artist_id.as_ref(), |artist| {
-            artist.add_to_property(property, values)
-        })
-    }
-
-    pub fn remove_from_artist_property<Id: AsRef<ArtistId>, S: AsRef<str>>(
-        &mut self,
-        artist_id: Id,
-        property: S,
-        values: Vec<S>,
-    ) -> Result<(), Error> {
-        self.update_artist(artist_id.as_ref(), |artist| {
-            artist.remove_from_property(property, values)
-        })
-    }
-
-    pub fn set_artist_property<Id: AsRef<ArtistId>, S: AsRef<str> + Into<String>>(
-        &mut self,
-        artist_id: Id,
-        property: S,
-        values: Vec<S>,
-    ) -> Result<(), Error> {
-        self.update_artist(artist_id.as_ref(), |artist| {
-            artist.set_property(property, values)
-        })
-    }
-
-    pub fn clear_artist_property<Id: AsRef<ArtistId>, S: AsRef<str>>(
-        &mut self,
-        artist_id: Id,
-        property: S,
-    ) -> Result<(), Error> {
-        self.update_artist(artist_id.as_ref(), |artist| artist.clear_property(property))
-    }
-
-    pub fn set_album_seq<ArtistIdRef: AsRef<ArtistId>, AlbumIdRef: AsRef<AlbumId>>(
-        &mut self,
-        artist_id: ArtistIdRef,
-        album_id: AlbumIdRef,
-        seq: u8,
-    ) -> Result<(), Error> {
-        self.update_album_and(
-            artist_id.as_ref(),
-            album_id.as_ref(),
-            |album| album.set_seq(AlbumSeq(seq)),
-            |artist| artist.albums.sort_unstable(),
-            |_| {},
-        )
-    }
-
-    pub fn clear_album_seq<ArtistIdRef: AsRef<ArtistId>, AlbumIdRef: AsRef<AlbumId>>(
-        &mut self,
-        artist_id: ArtistIdRef,
-        album_id: AlbumIdRef,
-    ) -> Result<(), Error> {
-        self.update_album_and(
-            artist_id.as_ref(),
-            album_id.as_ref(),
-            |album| album.clear_seq(),
-            |artist| artist.albums.sort_unstable(),
-            |_| {},
-        )
-    }
 }
 
 #[cfg(test)]
diff --git a/src/core/musichoard/library.rs b/src/core/musichoard/library.rs
index d93c908..1ec70dc 100644
--- a/src/core/musichoard/library.rs
+++ b/src/core/musichoard/library.rs
@@ -11,7 +11,10 @@ use crate::core::{
         database::IDatabase,
         library::{ILibrary, Item, Query},
     },
-    musichoard::{base::IMusicHoardBasePrivate, Error, MusicHoard, NoDatabase},
+    musichoard::{
+        base::IMusicHoardBasePrivate, database::IMusicHoardDatabasePrivate, Error, MusicHoard,
+        NoDatabase,
+    },
 };
 
 impl<Library: ILibrary> MusicHoard<NoDatabase, Library> {
diff --git a/src/core/musichoard/mod.rs b/src/core/musichoard/mod.rs
index 04d1cd9..2812afa 100644
--- a/src/core/musichoard/mod.rs
+++ b/src/core/musichoard/mod.rs
@@ -7,6 +7,7 @@ mod library;
 pub mod builder;
 
 pub use base::IMusicHoardBase;
+pub use database::IMusicHoardDatabase;
 
 use std::{
     collections::HashMap,
diff --git a/src/lib.rs b/src/lib.rs
index c0db04b..59f5f3b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -8,7 +8,8 @@ pub use core::collection;
 pub use core::interface;
 
 pub use core::musichoard::{
-    builder::MusicHoardBuilder, Error, IMusicHoardBase, MusicHoard, NoDatabase, NoLibrary,
+    builder::MusicHoardBuilder, Error, IMusicHoardBase, IMusicHoardDatabase, MusicHoard,
+    NoDatabase, NoLibrary,
 };
 
 #[cfg(test)]
diff --git a/src/tui/lib.rs b/src/tui/lib.rs
index da98a94..535be10 100644
--- a/src/tui/lib.rs
+++ b/src/tui/lib.rs
@@ -1,6 +1,6 @@
 use musichoard::{
     collection::Collection, interface::database::IDatabase, interface::library::ILibrary,
-    IMusicHoardBase, MusicHoard,
+    IMusicHoardBase, IMusicHoardDatabase, MusicHoard,
 };
 
 #[cfg(test)]
@@ -20,7 +20,7 @@ impl<Database: IDatabase, Library: ILibrary> IMusicHoard for MusicHoard<Database
     }
 
     fn reload_database(&mut self) -> Result<(), musichoard::Error> {
-        Self::reload_database(self)
+        <Self as IMusicHoardDatabase>::reload_database(self)
     }
 
     fn get_collection(&self) -> &Collection {
diff --git a/tests/lib.rs b/tests/lib.rs
index a3046f6..ddfc80f 100644
--- a/tests/lib.rs
+++ b/tests/lib.rs
@@ -9,7 +9,7 @@ mod testlib;
 use musichoard::{
     database::json::{backend::JsonDatabaseFileBackend, JsonDatabase},
     library::beets::{executor::BeetsLibraryProcessExecutor, BeetsLibrary},
-    IMusicHoardBase, MusicHoard,
+    IMusicHoardBase, IMusicHoardDatabase, MusicHoard,
 };
 
 use crate::testlib::COLLECTION;