Playback without stopping current playback

Is there a way to trigger playback of a waveform, then trigger a new playback while the first is still playing - with ONE HAND? I’m using a laptop to trigger a waveform in a musical performance and need my other hand to play percussion… Thanks!

No. But if the second event is at all predictable, you can put it on a second track under the first one. Audacity will play them both and you can slide them around earlier and later with the Time Shift Tool (two sideways black arrows).