Toolbar and transport controls

The strip across the top of the window, left to right. (Keyboard equivalents are in Keyboard shortcuts.)

Transport and project

Control	What it does
☰ (browser)	Toggle the left Browser sidebar — Templates, Demos, Plugins, Samples, Presets, Favorites
File	Open the File menu
Play	Start / pause playback in place (swaps to a Pause icon while playing)
Stop	Stop and return the playhead to the start; also finalizes an active recording or session capture
Record	In Arrange: record MIDI into the selected instrument track (and any armed audio tracks). In Session: capture the launched clips onto the arrangement
BPM	The tempo field — type a value or use the arrows (40–260 BPM)
Position	The playhead readout, as bar . beat . tick

Add a track

Each button adds a track; they differ only in the sound source.

Control	What it does
+ Synth	New instrument track — choose Surge XT (full editor) or the Basic synth
+ Sample	Load a .wav / .aif / .flac into a sampler track
+ SFZ	Load an .sfz multisampled instrument (native sfizz)
+ Audio	Import an audio file as a new audio track
+ Plugin	Host a VST3/LV2 instrument (or Rescan plugins)

See What to use for what to choose.

Musical and utility

Control	What it does
Scale root / Scale name	Set the project scale (root + type); drives snap-to-scale and piano-roll highlighting
Metro	Toggle the metronome click (accented downbeat)
Loop	Toggle transport looping over the loop region
Panic	All-notes-off on every track (also Ctrl+.)
Maps	Open the Mappings window — list, bypass, re-range, or remove MIDI/OSC maps and LFO routes
Mixer	Show / hide the embedded Mixer view

The status bar

The 22-pixel strip along the bottom shows, left to right: the project name (or Untitled), an unsaved dot when there are unsaved edits, the git branch and uncommitted/ahead/behind state once the project is a repo, and the Gloopy version on the right. Full details in Version your project with git.