syncing two tracks?

This will be my first time syncing two tracks. The first track has a drum beat with a stable, consistent tempo. The second track is a piano-played piece with varying tempo. I want the piano-piece to match the tempo of the drum beat for the whole song. The only way I know to do this is using the tempo track and speeding up/slowing down parts of the piano track to match the drumbeat.

Is there an easier way to do this? Thanks.

You would have been good had the piano and drum played to a metronome. Having them wander during the song is going to be very interesting to fix.