diff --git a/Cargo.lock b/Cargo.lock
index f6b817b..08d3641 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5,3 +5,71 @@ version = 3
 [[package]]
 name = "musichoard"
 version = "0.1.0"
+dependencies = [
+ "serde",
+ "uuid",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.54"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e472a104799c74b514a57226160104aa483546de37e839ec50e3c2e41dd87534"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4424af4bf778aae2051a77b60283332f386554255d722233d09fbfc7e30da2fc"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "serde"
+version = "1.0.159"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3c04e8343c3daeec41f58990b9d77068df31209f2af111e059e9fe9646693065"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.159"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4c614d17805b093df4b147b51339e7e44bf05ef59fba1e45d83500bcfb4d8585"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "syn"
+version = "2.0.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "21e3787bb71465627110e7d87ed4faaa36c1f61042ee67badb9e2ef173accc40"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e5464a87b239f13a63a501f2701565754bae92d243d4bb7eb12f6d57d2269bf4"
+
+[[package]]
+name = "uuid"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1674845326ee10d37ca60470760d4288a6f80f304007d92e5c53bab78c9cfd79"
+dependencies = [
+ "serde",
+]
diff --git a/Cargo.toml b/Cargo.toml
index 4321e78..03065c7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,3 +6,5 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+serde = { version = "1.0", features = ["derive"] }
+uuid = { version = "1.3", features = ["serde"] }
diff --git a/src/lib.rs b/src/lib.rs
index 7d12d9a..d7c1a7d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,14 +1,50 @@
-pub fn add(left: usize, right: usize) -> usize {
-    left + right
+use serde::{Deserialize, Serialize};
+use uuid;
+
+/// The [MusicBrainz Identifier](https://musicbrainz.org/doc/MusicBrainz_Identifier).
+type Mbid = uuid::Uuid;
+
+/// An artist. May be linked to MusicBrainz.
+#[derive(Deserialize, Serialize)]
+pub struct Artist {
+    pub name: String,
+    pub mbid: Option<Mbid>,
 }
 
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn it_works() {
-        let result = add(2, 2);
-        assert_eq!(result, 4);
-    }
+/// A single track on a release.
+#[derive(Deserialize, Serialize)]
+pub struct Track {
+    pub number: u32,
+    pub title: String,
+    pub artist: Artist,
+}
+
+/// MusicHoard release corresponds to MusicBrainz' concept of a release. However, it does not link
+/// to MusicBrainz as the intention of MusicHoard is to manage releases locally.
+#[derive(Deserialize, Serialize)]
+pub struct Release {
+    pub title: String,
+    pub artist: String,
+    pub tracks: Vec<Track>,
+}
+
+/// MusicHoard uses MusicBrainz [primary release group
+/// type](https://musicbrainz.org/doc/Release_Group/Type)
+#[derive(Deserialize, Serialize)]
+pub enum ReleaseGroupType {
+    Album,
+    Ep,
+    Single,
+    Other,
+}
+
+/// MusicHoard uses MusicBrainz' [Release Group concept](https://musicbrainz.org/doc/Release_Group).
+#[derive(Deserialize, Serialize)]
+pub struct ReleaseGroup {
+    pub r#type: ReleaseGroupType,
+    pub title: String,
+    pub artist: Artist,
+    pub year: u32,
+    pub mbid: Option<Mbid>,
+    pub releases: Vec<Release>,
 }