diff --git a/Cargo.toml b/Cargo.toml
index 60ed4b0..896c159 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,6 +23,7 @@ thiserror = "1.0.64"
 derive-new = "0.7.0"
 naan = "0.1.32"
 lazy_static = "1.5.0"
+tune = "0.35.0"
 
 [features]
 default = ["play", "save"]
diff --git a/poc/Ancient Greek Didymus Chromatic.scl b/poc/Ancient Greek Didymus Chromatic.scl
new file mode 100755
index 0000000..c43c603
--- /dev/null
+++ b/poc/Ancient Greek Didymus Chromatic.scl	
@@ -0,0 +1,12 @@
+! C:\Audio\Tunings\MTS Packs\World Scales Pack\scl\Ancient Greek Didymus Chromatic.scl
+!
+Didymus' Chromatic
+ 7
+!
+ 16/15
+ 10/9
+ 4/3
+ 3/2
+ 8/5
+ 5/3
+ 2/1
diff --git a/poc/Ancient Greek.kbm b/poc/Ancient Greek.kbm
new file mode 100755
index 0000000..23c3f4c
--- /dev/null
+++ b/poc/Ancient Greek.kbm	
@@ -0,0 +1,28 @@
+! Ancient Greek scales on E (white notes)
+! Size of map:
+12
+! First MIDI note number to retune:
+0
+! Last MIDI note number to retune:
+127
+! Middle note where the first entry in the mapping is mapped to:
+64
+! Reference note for which frequency is given:
+64
+! Frequency to tune the above note to (floating point e.g. 440.0):
+329.627557
+! Scale degree to consider as formal octave:
+7
+! Mapping.
+0
+1
+1
+2
+2
+3
+3
+4
+5
+5
+6
+6
diff --git a/poc/complete.yml b/poc/complete.yml
new file mode 100644
index 0000000..e53bf17
--- /dev/null
+++ b/poc/complete.yml
@@ -0,0 +1,57 @@
+# fixed
+instruments:
+  # instrument name
+  sine:
+    # fixed
+    expr: sin(2*PI*f*t) # instrument formula (f is the frequency in Hertz, t is the time in seconds)
+  square:
+    expr: v*abs(sin(2*PI*f*t))
+    # fixed
+    vars:
+      # name of the variable
+      v: 1 # initial value of the variable
+scl:
+  Didymus: poc/Ancient Greek Didymus Chromatic.scl
+kbm:
+  Greek: poc/Ancient Greek.kbm
+channels:
+  melody:
+    instr: sine
+    score:
+      notes: cCdDefFgGaAb
+      sheet: |
+        aabc.
+        'ab°A
+        +d+d+d---
+        /ff/f\\
+        ab>c<ba
+        ;this is a comment (or lyrics whatever),
+        C:CC
+        (3deff)
+        (deff)
+        [ffe]
+        {l 1-cos((PI*x)/2),acced}
+        abbc!o5cc!v15feed!l4fedd!t60Gdd
+
+        ; syntax :
+        rest: .
+        pizz.: '°
+        volume: +-
+        length: /\
+        octave: ><
+        comment?: ;,
+        start here: ':'
+        slope: {MODIFIER EXPR score}
+        note modifier prefix: n
+        volume modifier prefix: v
+        octave modifier prefix: o
+        length modifier prefix: l
+        tempo modifier prefix: t
+        loop: ()
+        loop with count: (COUNT score)
+        tuple: []
+        modifier: !
+        volume modifier prefix: v
+        octave modifier prefix: o
+        length modifier prefix: l
+        tempo modifier prefix: t,
diff --git a/poc/nokbm.yml b/poc/nokbm.yml
new file mode 100644
index 0000000..3b8165a
--- /dev/null
+++ b/poc/nokbm.yml
@@ -0,0 +1,55 @@
+# fixed
+instruments:
+  # instrument name
+  sine:
+    # fixed
+    expr: sin(2*PI*f*t) # instrument formula (f is the frequency in Hertz, t is the time in seconds)
+  square:
+    expr: v*abs(sin(2*PI*f*t))
+    # fixed
+    vars:
+      # name of the variable
+      v: 1 # initial value of the variable
+scl:
+  Greek: poc/Ancient Greek Didymus Chromatic.scl
+channels:
+  melody:
+    instr: sine
+    score:
+      notes: cCdDefFgGaAb
+      sheet: |
+        aabc.
+        'ab°A
+        +d+d+d---
+        /ff/f\\
+        ab>c<ba
+        ;this is a comment (or lyrics whatever),
+        C:CC
+        (3deff)
+        (deff)
+        [ffe]
+        {l 1-cos((PI*x)/2),acced}
+        abbc!o5cc!v15feed!l4fedd!t60Gdd
+
+        ; syntax :
+        rest: .
+        pizz.: '°
+        volume: +-
+        length: /\
+        octave: ><
+        comment?: ;,
+        start here: ':'
+        slope: {MODIFIER EXPR score}
+        note modifier prefix: n
+        volume modifier prefix: v
+        octave modifier prefix: o
+        length modifier prefix: l
+        tempo modifier prefix: t
+        loop: ()
+        loop with count: (COUNT score)
+        tuple: []
+        modifier: !
+        volume modifier prefix: v
+        octave modifier prefix: o
+        length modifier prefix: l
+        tempo modifier prefix: t,
diff --git a/poc/poc.yml b/poc/noscl.yml
similarity index 97%
rename from poc/poc.yml
rename to poc/noscl.yml
index 87f09d9..2bee6f6 100644
--- a/poc/poc.yml
+++ b/poc/noscl.yml
@@ -10,6 +10,8 @@ instruments:
     vars:
       # name of the variable
       v: 1 # initial value of the variable
+kbm:
+  Greek: poc/Ancient Greek.kbm
 channels:
   melody:
     instr: sine
diff --git a/poc/nothing.yml b/poc/nothing.yml
new file mode 100644
index 0000000..24916a4
--- /dev/null
+++ b/poc/nothing.yml
@@ -0,0 +1,49 @@
+# fixed
+instruments:
+  # instrument name
+  sine:
+    # fixed
+    expr: sin(2*PI*f*t) # instrument formula (f is the frequency in Hertz, t is the time in seconds)
+  square:
+    expr: v*abs(sin(2*PI*f*t))
+channels:
+  melody:
+    instr: sine
+    score:
+      notes: cCdDefFgGaAb
+      sheet: |
+        aabc.
+        'ab°A
+        +d+d+d---
+        /ff/f\\
+        ab>c<ba
+        ;this is a comment (or lyrics whatever),
+        C:CC
+        (3deff)
+        (deff)
+        [ffe]
+        {l 1-cos((PI*x)/2),acced}
+        abbc!o5cc!v15feed!l4fedd!t60Gdd
+
+        ; syntax :
+        rest: .
+        pizz.: '°
+        volume: +-
+        length: /\
+        octave: ><
+        comment?: ;,
+        start here: ':'
+        slope: {MODIFIER EXPR score}
+        note modifier prefix: n
+        volume modifier prefix: v
+        octave modifier prefix: o
+        length modifier prefix: l
+        tempo modifier prefix: t
+        loop: ()
+        loop with count: (COUNT score)
+        tuple: []
+        modifier: !
+        volume modifier prefix: v
+        octave modifier prefix: o
+        length modifier prefix: l
+        tempo modifier prefix: t,
diff --git a/src/bng.rs b/src/bng.rs
index d3a2a8d..31cb5ec 100644
--- a/src/bng.rs
+++ b/src/bng.rs
@@ -7,75 +7,37 @@ use fasteval::{Compiler, Instruction};
 pub(super) use instrument::Instrument;
 pub(super) use score::Atom;
 use score::Atoms;
-#[cfg(debug_assertions)]
-use serde::Serialize;
 use serde::{de::Visitor, Deserialize};
+use tune::scala::{Kbm, Scl};
 
+mod de;
 mod instrument;
 mod score;
 
 #[derive(Debug, PartialEq, Wrapper, From)]
 pub struct Expression(Instruction);
 
-#[cfg(debug_assertions)]
-impl Serialize for Expression {
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: serde::Serializer,
-    {
-        let expr_str = String::new();
-        serializer.serialize_str(&format!("{:#?}", self.0))
-    }
-}
-
-impl<'de> Deserialize<'de> for Expression {
-    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
-    where
-        D: serde::Deserializer<'de>,
-    {
-        deserializer.deserialize_str(ExpressionVisitor)
-    }
-}
-
-pub struct ExpressionVisitor;
-
-impl<'de> Visitor<'de> for ExpressionVisitor {
-    type Value = Expression;
-    fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
-        formatter
-            .write_str("a math expression following fasteval syntax (https://docs.rs/fasteval)")
-    }
-    fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
-    where
-        E: serde::de::Error,
-    {
-        v.parse().map_err(serde::de::Error::custom)
-    }
-}
-
-impl FromStr for Expression {
-    type Err = fasteval::Error;
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let parser = fasteval::Parser::new();
-        let mut slab = fasteval::Slab::new();
-        Ok(parser
-            .parse(s, &mut slab.ps)?
-            .from(&slab.ps)
-            .compile(&slab.ps, &mut slab.cs)
-            .into())
-    }
-}
-
 #[derive(new, Deserialize)]
-#[cfg_attr(debug_assertions, derive(Serialize, Debug))]
+#[cfg_attr(debug_assertions, derive(Debug))]
 pub(super) struct Channel {
     instr: String,
     score: Atoms,
 }
 
-#[derive(Deserialize)]
-#[cfg_attr(debug_assertions, derive(new, Debug, Serialize))]
+#[derive(Deserialize, Default)]
+#[cfg_attr(debug_assertions, derive(new, Debug))]
+#[serde(deny_unknown_fields)]
+#[serde(default)]
 pub(super) struct BngFile {
     instruments: HashMap<String, Instrument>,
     channels: HashMap<String, Channel>,
+    #[serde(rename = "scl")]
+    scales: HashMap<String, Scale>,
+    #[serde(rename = "kbm")]
+    keyboard_mappings: HashMap<String, KeyboardMapping>,
 }
+
+#[derive(Debug, Wrapper, From)]
+struct Scale(Scl);
+#[derive(Debug, Wrapper, From)]
+struct KeyboardMapping(Kbm);
diff --git a/src/bng/de.rs b/src/bng/de.rs
new file mode 100644
index 0000000..29844ff
--- /dev/null
+++ b/src/bng/de.rs
@@ -0,0 +1,63 @@
+use std::{fmt::Display, marker::PhantomData, str::FromStr};
+
+use fasteval::Compiler;
+use serde::{de::Visitor, Deserialize};
+
+use super::{Expression, KeyboardMapping, Scale};
+
+mod from_str;
+
+struct FromStrVisitor<'a, V> {
+    expecting: &'a str,
+    phantom: PhantomData<V>,
+}
+
+impl<'a, V> FromStrVisitor<'a, V> {
+    fn new(expecting: &'a str) -> Self {
+        FromStrVisitor {
+            expecting,
+            phantom: PhantomData,
+        }
+    }
+}
+
+impl<'de, 'a, V> Visitor<'de> for FromStrVisitor<'a, V>
+where
+    V: FromStr,
+    <V as FromStr>::Err: Display,
+{
+    type Value = V;
+    fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+        formatter.write_str(self.expecting)
+    }
+    fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+    where
+        E: serde::de::Error,
+    {
+        v.parse::<V>().map_err(serde::de::Error::custom)
+    }
+}
+
+macro_rules! deserialize_fromstr_expect {
+    ($type:ty, $expect:literal) => {
+        impl<'de> serde::de::Deserialize<'de> for $type {
+            fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+            where
+                D: serde::Deserializer<'de>,
+            {
+                deserializer.deserialize_str(FromStrVisitor::new($expect))
+            }
+        }
+    };
+}
+
+deserialize_fromstr_expect!(
+    Expression,
+    "a math expression following fasteval syntax (https://docs.rs/fasteval)"
+);
+
+deserialize_fromstr_expect!(Scale, "a .scl file containing a Scala scale");
+deserialize_fromstr_expect!(
+    KeyboardMapping,
+    "a .kbm file containing a Scala keyboard mapping"
+);
diff --git a/src/bng/de/from_str.rs b/src/bng/de/from_str.rs
new file mode 100644
index 0000000..f2e9996
--- /dev/null
+++ b/src/bng/de/from_str.rs
@@ -0,0 +1,53 @@
+use std::{fs::File, io, str::FromStr};
+
+use amplify::{From, Wrapper};
+use fasteval::Compiler;
+use thiserror::Error;
+use tune::scala::{Kbm, KbmImportError, Scl, SclImportError};
+
+use crate::bng::{KeyboardMapping, Scale};
+
+use super::super::Expression;
+
+impl FromStr for Expression {
+    type Err = fasteval::Error;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let parser = fasteval::Parser::new();
+        let mut slab = fasteval::Slab::new();
+        Ok(parser
+            .parse(s, &mut slab.ps)?
+            .from(&slab.ps)
+            .compile(&slab.ps, &mut slab.cs)
+            .into())
+    }
+}
+
+#[derive(Debug, Error)]
+#[error("{0:?}")]
+pub struct ScalaImportError<E>(E);
+
+impl FromStr for Scale {
+    type Err = ScalaImportError<SclImportError>;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Scl::import(
+            File::open(s)
+                .map_err(Into::into)
+                .map_err(ScalaImportError)?,
+        )
+        .map(Scale::from)
+        .map_err(ScalaImportError)
+    }
+}
+
+impl FromStr for KeyboardMapping {
+    type Err = ScalaImportError<KbmImportError>;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Kbm::import(
+            File::open(s)
+                .map_err(Into::into)
+                .map_err(ScalaImportError)?,
+        )
+        .map(KeyboardMapping::from)
+        .map_err(ScalaImportError)
+    }
+}
diff --git a/src/bng/instrument.rs b/src/bng/instrument.rs
index dce3256..6dc9cc8 100644
--- a/src/bng/instrument.rs
+++ b/src/bng/instrument.rs
@@ -1,15 +1,13 @@
 use std::collections::HashMap;
 
+#[cfg(debug_assertions)]
+use super::Expression as Instruction;
 use derive_new::new;
 use derived_deref::Deref;
 use serde::Deserialize;
-#[cfg(debug_assertions)]
-use serde::Serialize;
-
-use super::Expression as Instruction;
 
 #[derive(Deref, new, Deserialize)]
-#[cfg_attr(debug_assertions, derive(Serialize, Debug))]
+#[cfg_attr(debug_assertions, derive(Debug))]
 pub struct Instrument {
     #[target]
     expr: Instruction,
diff --git a/src/bng/score.rs b/src/bng/score.rs
index 38b7609..71ffa77 100644
--- a/src/bng/score.rs
+++ b/src/bng/score.rs
@@ -15,8 +15,6 @@ use nom::{
     multi::many0,
     sequence::{preceded, terminated},
 };
-#[cfg(debug_assertions)]
-use serde::Serialize;
 use serde::{
     de::{self as serde_de, Visitor},
     Deserialize,
@@ -31,7 +29,7 @@ pub use de::*;
 use super::Expression as Instruction;
 
 #[derive(Deref, From, Default, Clone)]
-#[cfg_attr(debug_assertions, derive(Serialize, Debug, PartialEq))]
+#[cfg_attr(debug_assertions, derive(Debug, PartialEq))]
 pub struct Atoms(Vec<Atom>);
 
 #[cfg_attr(debug_assertions, derive(Debug, PartialEq))]
@@ -61,16 +59,6 @@ impl Clone for Atom {
     }
 }
 
-#[cfg(debug_assertions)]
-impl Serialize for Atom {
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: serde::Serializer,
-    {
-        serializer.serialize_str("atom")
-    }
-}
-
 #[derive(Clone, ModifierParser)]
 #[cfg_attr(debug_assertions, derive(Debug, PartialEq))]
 pub enum Modifier {
diff --git a/src/main.rs b/src/main.rs
index 256e7f8..2f50c07 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -28,26 +28,3 @@ fn main() -> Result<(), Error> {
     }
     Ok(())
 }
-
-#[cfg(debug_assertions)]
-fn bngfile_generator() -> BngFile {
-    BngFile::new(
-        HashMap::from([
-            (
-                "sine".to_string(),
-                Instrument::new("sin(2*PI*f*t)".parse().unwrap(), None),
-            ),
-            (
-                "square".to_string(),
-                Instrument::new(
-                    "v*abs(sin(2*PI*f*t))".parse().unwrap(),
-                    Some(HashMap::from([("v".to_string(), 1f64)])),
-                ),
-            ),
-        ]),
-        HashMap::<String, Channel>::from([(
-            "melody".to_string(),
-            Channel::new("sine".to_string(), vec![].into()),
-        )]),
-    )
-}