Fisxing off-beat in an existing song

Hi all,

Flanker305 here, new to the forum, first post.
Hi all :smiley:

I know Audacity for quite some time, but encountered a problem reventy I can’t take care of.
I have a WAV of an existing poprocksong played by a band.
The BPM reads 122,09.

I want to remake this track and add a beat to it. So I used LMMS to create a beat (122,09 BPM) and put it over the song.
At first the beat was off, and the grid in LMMS didn’t allow me to sync the tracks properly.
So I went over to my good old Audacity to match te two waves to perfection.

And here it is: eventhough the BPM reads 122.09 on both wavs, the beats of the drumkit in the song eventually don’t match my own beat anymore.
The beat created in LMMS can’t be off, so it must be the song.

I have been moderator on the forums of for quite some time.
I know what a pain it can be to tell all those folks about the search engine of the forum while they happily keep posting already answered questions.
I did a little research but coudn’t find an answer to this particular question:

Is there a way to ‘stretch and crop’ the entire song (where required), and change the tempo - only at the points where it’s off - to match the beat again?

Thanks for having me - pointing me in the right direction on the forums or a straight away answer would be highly appreciated.
Have yourself a lovely day!

Audacity includes several effects for “stretching” the sound in various ways: