diff --git a/CHANGELOG.md b/CHANGELOG.md
index 02365e9..59afe2a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## bliss 0.4.4
+* Make features' version public.
+
+## bliss 0.4.3
+* Add features' version on each Song instance.
+
 ## bliss 0.4.2
 * Add a binary example to easily make playlists.
 
diff --git a/Cargo.lock b/Cargo.lock
index eace266..70ea4da 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -86,7 +86,7 @@ checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 
 [[package]]
 name = "bliss-audio"
-version = "0.4.2"
+version = "0.4.4"
 dependencies = [
  "anyhow",
  "bliss-audio-aubio-rs",
diff --git a/Cargo.toml b/Cargo.toml
index fa3c5bd..4528dd2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "bliss-audio"
-version = "0.4.2"
+version = "0.4.4"
 authors = ["Polochon-street <polochonstreet@gmx.fr>"]
 edition = "2018"
 license = "GPL-3.0-only"
diff --git a/src/chroma.rs b/src/chroma.rs
index ff48e61..75bf619 100644
--- a/src/chroma.rs
+++ b/src/chroma.rs
@@ -321,7 +321,7 @@ fn estimate_tuning(
     resolution: f64,
     bins_per_octave: u32,
 ) -> BlissResult<f64> {
-    let (pitch, mag) = pip_track(sample_rate, &spectrum, n_fft)?;
+    let (pitch, mag) = pip_track(sample_rate, spectrum, n_fft)?;
 
     let (filtered_pitch, filtered_mag): (Vec<N64>, Vec<N64>) = pitch
         .iter()
diff --git a/src/distance.rs b/src/distance.rs
index 5933b7b..6e42cc3 100644
--- a/src/distance.rs
+++ b/src/distance.rs
@@ -107,7 +107,7 @@ pub fn dedup_playlist_custom_distance(
     distance: impl DistanceMetric,
 ) {
     songs.dedup_by(|s1, s2| {
-        n32(s1.custom_distance(&s2, &distance)) < distance_threshold.unwrap_or(0.05)
+        n32(s1.custom_distance(s2, &distance)) < distance_threshold.unwrap_or(0.05)
             || (s1.title.is_some()
                 && s2.title.is_some()
                 && s1.artist.is_some()
diff --git a/src/lib.rs b/src/lib.rs
index f87f26b..7e443b3 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -85,6 +85,10 @@ pub use song::{Analysis, AnalysisIndex, Song, NUMBER_FEATURES};
 
 const CHANNELS: u16 = 1;
 const SAMPLE_RATE: u32 = 22050;
+/// Stores the current version of bliss-rs' features.
+/// It is bumped every time one or more feature is added, updated or removed,
+/// so plug-ins can rescan libraries when there is a major change.
+pub const FEATURES_VERSION: u16 = 1;
 
 #[derive(Error, Clone, Debug, PartialEq)]
 /// Umbrella type for bliss error types
diff --git a/src/library.rs b/src/library.rs
index 4631fed..a719232 100644
--- a/src/library.rs
+++ b/src/library.rs
@@ -56,7 +56,7 @@ pub trait Library {
 
         for song in &songs {
             if let Some(album) = &song.album {
-                if let Some(analysis) = albums_analysis.get_mut(&album as &str) {
+                if let Some(analysis) = albums_analysis.get_mut(album as &str) {
                     analysis
                         .push_row(song.analysis.as_arr1().view())
                         .map_err(|e| {
@@ -65,7 +65,7 @@ pub trait Library {
                 } else {
                     let mut array = Array::zeros((1, song.analysis.as_arr1().len()));
                     array.assign(&song.analysis.as_arr1());
-                    albums_analysis.insert(&album, array);
+                    albums_analysis.insert(album, array);
                 }
             }
         }
@@ -92,7 +92,7 @@ pub trait Library {
         albums.sort_by_key(|(_, analysis)| {
             n32(euclidean_distance(
                 first_analysis.as_ref().unwrap(),
-                &analysis,
+                analysis,
             ))
         });
         let albums = albums.get(..playlist_length).unwrap_or(&albums);
diff --git a/src/song.rs b/src/song.rs
index cd98517..319e73a 100644
--- a/src/song.rs
+++ b/src/song.rs
@@ -12,7 +12,7 @@ extern crate ffmpeg_next as ffmpeg;
 extern crate ndarray;
 extern crate ndarray_npy;
 
-use super::CHANNELS;
+use crate::{CHANNELS, FEATURES_VERSION};
 use crate::chroma::ChromaDesc;
 use crate::distance::{euclidean_distance, DistanceMetric};
 use crate::misc::LoudnessDesc;
@@ -61,6 +61,10 @@ pub struct Song {
     pub genre: Option<String>,
     /// bliss analysis results
     pub analysis: Analysis,
+    /// Version of the features the song was analyzed with.
+    /// A simple integer that is bumped every time a breaking change
+    /// is introduced in the features.
+    pub features_version: u16,
 }
 
 #[derive(Debug, EnumIter, EnumCount)]
@@ -251,6 +255,7 @@ impl Song {
             track_number: raw_song.track_number,
             genre: raw_song.genre,
             analysis: Song::analyse(raw_song.sample_array)?,
+            features_version: FEATURES_VERSION,
         })
     }
 
@@ -289,7 +294,7 @@ impl Song {
                     .step_by(BPMDesc::HOP_SIZE);
 
                 for window in windows {
-                    tempo_desc.do_(&window)?;
+                    tempo_desc.do_(window)?;
                 }
                 Ok(tempo_desc.get_value())
             });
@@ -310,7 +315,7 @@ impl Song {
                     .windows(SpectralDesc::WINDOW_SIZE)
                     .step_by(SpectralDesc::HOP_SIZE);
                 for window in windows {
-                    spectral_desc.do_(&window)?;
+                    spectral_desc.do_(window)?;
                 }
                 let centroid = spectral_desc.get_centroid();
                 let rolloff = spectral_desc.get_rolloff();
@@ -330,7 +335,7 @@ impl Song {
                     let windows = sample_array.chunks(LoudnessDesc::WINDOW_SIZE);
 
                     for window in windows {
-                        loudness_desc.do_(&window);
+                        loudness_desc.do_(window);
                     }
                     Ok(loudness_desc.get_value())
                 });
@@ -657,6 +662,7 @@ mod tests {
         for (x, y) in song.analysis.as_vec().iter().zip(expected_analysis) {
             assert!(0.01 > (x - y).abs());
         }
+        assert_eq!(FEATURES_VERSION, song.features_version);
     }
 
     fn _test_decode(path: &Path, expected_hash: &[u8]) {
diff --git a/src/timbral.rs b/src/timbral.rs
index a70e0c2..2624207 100644
--- a/src/timbral.rs
+++ b/src/timbral.rs
@@ -204,12 +204,12 @@ impl SpectralDesc {
         self.values_rolloff.push(freq);
 
         let cvec: CVec = fftgrain.as_slice().into();
-        let geo_mean = geometric_mean(&cvec.norm());
+        let geo_mean = geometric_mean(cvec.norm());
         if geo_mean == 0.0 {
             self.values_flatness.push(0.0);
             return Ok(());
         }
-        let flatness = geo_mean / mean(&cvec.norm());
+        let flatness = geo_mean / mean(cvec.norm());
         self.values_flatness.push(flatness);
         Ok(())
     }
diff --git a/src/utils.rs b/src/utils.rs
index 4ac8181..72444ae 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -29,7 +29,7 @@ pub(crate) fn stft(signal: &[f32], window_length: usize, hop_length: usize) -> A
         (signal.len() as f32 / hop_length as f32).ceil() as usize,
         window_length / 2 + 1,
     ));
-    let signal = reflect_pad(&signal, window_length / 2);
+    let signal = reflect_pad(signal, window_length / 2);
 
     // Periodic, so window_size + 1
     let mut hann_window = Array::zeros(window_length + 1);
@@ -45,7 +45,7 @@ pub(crate) fn stft(signal: &[f32], window_length: usize, hop_length: usize) -> A
         .step_by(hop_length)
         .zip(stft.rows_mut())
     {
-        let mut signal = (arr1(&window) * &hann_window).mapv(|x| Complex::new(x, 0.));
+        let mut signal = (arr1(window) * &hann_window).mapv(|x| Complex::new(x, 0.));
         match signal.as_slice_mut() {
             Some(s) => fft.process(s),
             None => {