In Ableton Live when you hit the Space Bar it triggers the transport to start or stop. Each time you hit the Space Bar the song begins playing from the last Insert Marker. I find this very useful as you can make changes to a section and listen again to the same section quickly. But what if your playing a live show and you pause the music or you know your happy with a section you have just changed? You want the arrangement to keep playing from the location you stopped it right? Hold down shift and hit the Space Bar and presto your song keeps playing without returning to the last insert marker!
Arrangement playback can also be toggled on and off by pressing the keyboard’s space bar. To continue playback from the position where it last stopped, rather than from the insert marker, hold down the shift modifier while pressing the space bar. – Ableton Live User Manual
photo credit: gottlieb