Double-click the Ableton Live icon on the desktop to launch the program. Click "File," then "Open." Navigate to the project that you're working on and double-click it to open.
Press "Tab" to switch to Arrangement View, if it's not already open. Move the mouse pointer above the time line; a magnifying glass appears. Click and hold the mouse, then move the mouse upward until Ableton displays the entire song.
Right-click inside the time line at the beginning of the song. Click "Add Locator." Type "Start" into the locator text box that appears, then press "Enter."
Click the "KEY" button in the top-right corner of the Ableton window to enable the key map. Click on the locator that you added, then press the key you want to use to jump back to the beginning of the song. Click the "KEY" button again.
Click the "Play" button to play the song. Press the assigned hot key at any point during playback to jump back to the beginning of the song.