how can you permanently change the tempo a track?

i want to change the tempo of all my tracks to be with in a 2-4 bpm range how can i do this?

 

to avoid playing the lengthy process of playing them all at a different pitch and recording them in traktor, you'd have to open every single one in an audio editor or DAW like audacity/cubase/ableton etc and process them (pitch up or down or time stretch) then export the results as a new audio file.
however you do it, it's a highly time consuming process that will inevitably degrade your music collections audio quality.
far from ideal.
why are you interested btw?

 

too lazy to mix like everyone else?

 

the reason i want to change the pitch of everything is that i want to get things grouped into a common key.

and im just going to ignore what the other a-hole said.

 

i'm WELL confused; do you want them to have a common tempo or common pitch?

 

i guess it would be the pitch

 

Let's change of vocabulary.. do you want to change the speed of the track (tempo) or the heigth of the note/key (pitch)

In both case, the process can be done with Ableton live, but as Trance Alba said, it's destructive and quality of the tracks is impaired.

 

Can you not just mix with the keylock on? It'll sound the same, and you won't have destructively changed your tracks?