Making The Key Of Vocals In Ableton The Same

[kevzzz]

So I'm just polishing up my first mashup...but it sounds quite off

does anyone know to the change the key of a the two vocal tracks to make sure they are the same in Ableton 7?

Thanks in advance

[K.T.I.T.]

There are probably easier ways to do this but I would analyze them either manually by listening or use something like Mixed in Key and afterwards use the transpose function inside Ableton. The pitch feature is in the warp panel.
You can also use the Camelot key diagram or any normal key diagram as a reference to which keys sound harmonic without having to pitch too much.