diff --git a/Cargo.toml b/Cargo.toml
index b97ec445..c1285f0d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,11 +4,10 @@ edition = "2021"
 version = "0.2.0"
 
 [dependencies]
-#no_deadlocks = "1.3.2"
-#vst3 = "0.1.0"
 atomic_float = "1.0.0"
 backtrace = "0.3.72"
 better-panic = "0.3.0"
+clap = { version = "4.5.4", features = [ "derive" ] }
 clojure-reader = "0.1.0"
 crossterm = "0.27"
 jack = { path = "./rust-jack" }
@@ -19,14 +18,15 @@ palette = { version = "0.7.6", features = [ "random" ] }
 quanta = "0.12.3"
 rand = "0.8.5"
 ratatui = { version = "0.26.3", features = [ "unstable-widget-ref", "underline-color" ] }
-#suil-rs = { path = "../suil" }
 symphonia = { version = "0.5.4", features = [ "all" ] }
 toml = "0.8.12"
 uuid = { version = "1.10.0", features = [ "v4" ] }
-#vst = "0.4.0"
 wavers = "1.4.3"
+#no_deadlocks = "1.3.2"
+#suil-rs = { path = "../suil" }
+#vst = "0.4.0"
+#vst3 = "0.1.0"
 #winit = { version = "0.30.4", features = [ "x11" ] }
-clap = { version = "4.5.4", features = [ "derive" ] }
 
 [[bin]]
 name = "tek_arranger"
diff --git a/bin/cli_groovebox.rs b/bin/cli_groovebox.rs
index b001b633..bb46e003 100644
--- a/bin/cli_groovebox.rs
+++ b/bin/cli_groovebox.rs
@@ -9,6 +9,9 @@ pub struct GrooveboxCli {
     /// Whether to include a transport toolbar (default: true)
     #[arg(short, long, default_value_t = true)]
     transport: bool,
+    /// Whether to attempt to become transport master
+    #[arg(short, long, default_value_t = true)]
+    sync:      bool,
     /// MIDI outs to connect to MIDI input
     #[arg(short='i', long)]
     midi_from: Vec<String>,
@@ -31,7 +34,7 @@ pub struct GrooveboxCli {
 impl GrooveboxCli {
     fn run (&self) -> Usually<()> {
         Tui::run(JackClient::new("tek_groovebox")?.activate_with(|jack|{
-            let app  = tek::GrooveboxTui::try_from(jack)?;
+            let app = tek::GrooveboxTui::try_from(jack)?;
             jack.read().unwrap().client().connect_ports(&app.player.midi_outs[0], &app.sampler.midi_in)?;
             jack.connect_midi_from(&app.player.midi_ins[0],    &self.midi_from)?;
             jack.connect_midi_from(&app.sampler.midi_in,       &self.midi_from)?;
@@ -40,6 +43,12 @@ impl GrooveboxCli {
             jack.connect_audio_from(&app.sampler.audio_ins[1], &self.r_from)?;
             jack.connect_audio_to(&app.sampler.audio_outs[0],  &self.l_to)?;
             jack.connect_audio_to(&app.sampler.audio_outs[1],  &self.r_to)?;
+            if self.sync {
+                jack.read().unwrap().client().register_timebase_callback(false, |bbt, state, nframes, new_pos|{
+                    println!("\r{state:?} {nframes} {new_pos}");
+                    // TODO
+                })?
+            }
             Ok(app)
         })?)?;
         Ok(())
diff --git a/rust-jack b/rust-jack
index 5256af1d..5a913d4c 160000
--- a/rust-jack
+++ b/rust-jack
@@ -1 +1 @@
-Subproject commit 5256af1ddea221dd78f22e48c0a72a3842cad26d
+Subproject commit 5a913d4c97b18d51bd8175d1bcb55c1b0fd52cb1