if you're a learner, try playing for dancers.

Me [rhythm guitar & melodeon] & Dixie[piano accordian & b/c button accordion]play for a bunch of clog/morris dancers for 2 hours once a week.

The dancers, some of whom are beginners too, or if they're all learning a new dance; require both normal speed & also SLOW-er renditions of Marches,Reels,Polkas, & Jigs.

For our little band, it can be quite hard to play familiar stuff
S-L-O-W-L-Y but from time to time we've another novice button box player joining in, & she reports the slower pace/tempo/rythym is good for her to pick out the individual notes & basses/accompaniment- also from a bloke from Oswestry learning Anglo concertina who's sometimes come along to play when they're dancing out! [not practicing]