I know this is a pretty fundamental question but I'm pretty new to biab, so bear with me.

I've been trying to make a song so I can jam to the chords in Old Love by Eric Clapton, so I inputted the chords and chose real tracks from the list for piano and bass, but when I hit play the thing was a nightmare. The piano wasn't even close to being in time and the bass player was all over the place. But then when I chose a pre-selected style (slowbal) it was great. I'm not sure what I did wrong.

If I load a style then start selecting real tracks, my real tracks will replace the ones in the style, yes?

I'm going to have to watch the instructional videos again...