Well it wouldn't be from brain power... Concentrating uses barely any additional calories from what I've read.
That's more calories than it takes to run a mile too, although the mile would take a fraction of that hour.
I think I'd still buy 150-170 cal/hour of piano (or any instrument) playing.
To burn 150 calories you'll need to:
Just a google search on burning 150 calories...
1.Read for 1 hour and 43 minutes.
2.Watch television for 2 hours and 12 minutes.
3.Sleep for 2 hours and 27 minutes.
https://www.everydayhealth.com/fitness/basics/tips/15-ways-to-burn-150-calories.aspxYeah... Similar things here. Running, etc. is for 15 min, roughly.
But walking for 33-53 min is 150 cal.
Gardening for 30 min... 150 cal.
Home improvement of cleaning is 150 cal in 30 min.
And the list above is on this site... for doing nothing or next to nothing.
Maybe the question is... How many calories does piano practice burn compared to doing nothing? (BMR)
If sleep is 150 calories in 2.5 hr. That's pretty much nothing, except for whatever the brain starts doing when you're asleep. Still low power though, and the brain doesn't drain extra calories regardless of how hard it works. So dreaming hard wouldn't matter.
150cal/2.5hr
or 50 cal/hr for sleeping
vs. music practice at 150 cal/hr.
So music practice is burning an extra 100 cal/hr compared to doing nothing.
And the brain's not taking in extra, so these calories are be burned from physical activity. Physical activity can use fat (brain cannot from what I've read), so you could burn fat by practicing, although I'm thinking that's a pretty inefficient way to burn fat/calories.