In a duo using midi backing tracks, and the other guy is a drummer.

Tracks are a mix of commercial and homebrew, all to a greater or lesser extent adjusted to leave space for the drummer and myself to add meaningful contributions. Tempo and dynamics changes also added it required.

Over the years we have played a lot of ballroom dancing. Your tempos need to be rock solid and accuarate, and to do that we used a metronome until we felt confident we could do it freestyle.

The discipline this requires makes playing against a backing track much easier.

When I got my Ensoniqq ESQ1 I was recording some simple piano tracks to support an amateur music show. So I recorded myself and thought "that's not bad". Then I applied some quantization to tidy things up and discovered my tempo through the tunes was up and down like a yo-yo. Quite an eye opener!