diff --git a/src/cli/cli.rs b/src/cli/cli.rs
index eaeb75f..8c331dd 100644
--- a/src/cli/cli.rs
+++ b/src/cli/cli.rs
@@ -6,7 +6,7 @@ use std::{
     fs::File,
     io::{self, Cursor, Read, stdin},
     ops::Not,
-    str::{Bytes, FromStr},
+    str::FromStr,
 };
 
 use anyhow::anyhow;
@@ -47,7 +47,7 @@ pub(super) enum Cli {
 
 #[derive(Parser, Clone, Getters)]
 #[cfg_attr(debug_assertions, derive(Debug))]
-#[getset(get)]
+#[getset(get = "pub(super)")]
 pub(super) struct PlayOpts {
     /// Use this sheet music [default: stdin]
     #[command(flatten)]
@@ -72,7 +72,7 @@ pub(super) struct PlayOpts {
     /// Add a slope expression named NAME which mutates the VARIABLE with the result of EXPR each frame
     #[arg(short, long = "slope", value_name = "NAME:VARIABLE=EXPR", value_parser = parse_key_tuple::<LetterString, Letter, Expression>)]
     #[getset(skip)]
-    slopes: Vec<(String, (LetterString, Expression))>,
+    slopes: Vec<(LetterString, (char, Expression))>,
 }
 
 impl PlayOpts {
@@ -84,13 +84,15 @@ impl PlayOpts {
         self.macros.iter().map(|(c, s)| (c.as_ref(), s))
     }
 
-    pub(super) fn slopes(&self) -> impl Iterator<Item = (&String, (&String, &Expression))> {
-        self.slopes.iter().map(|(id, (s, e))| (id, (s.as_ref(), e)))
+    pub(super) fn slopes(&self) -> impl Iterator<Item = (&String, (&char, &Expression))> {
+        self.slopes
+            .iter()
+            .map(|(name, (v, e))| (name.as_ref(), (v, e)))
     }
 }
 
 impl InputGroup {
-    pub(super) fn get<'a>(&'a self) -> Box<dyn Read> {
+    pub(super) fn get(&self) -> Box<dyn Read> {
         self.input
             .as_ref()
             .map(|i| Box::new(i.clone().0) as Box<dyn Read>)
diff --git a/src/cli/main.rs b/src/cli/main.rs
index e0307e7..ddf5bb7 100644
--- a/src/cli/main.rs
+++ b/src/cli/main.rs
@@ -1,12 +1,22 @@
 mod cli;
-use clap::Parser;
+use bliplib::{compiler::VariableChange, parser::Parser};
+use clap::Parser as _;
 use cli::Cli;
 
 fn main() {
     let cli = Cli::parse();
     use Cli::*;
     match cli {
-        Play(play_opts) => todo!(),
+        Play(play_opts) => {
+            let parser = Parser::new(
+                play_opts.notes(),
+                play_opts
+                    .slopes()
+                    .map(|(s, (v, e))| (s, VariableChange(*v, e.clone())))
+                    .collect::<Vec<_>>(),
+                play_opts.variables().map(|(v, _)| *v).collect::<Vec<_>>(),
+            );
+        }
         Export(export_opts) => todo!(),
         Memo(memo) => todo!(),
     }