How do I speed up (part of) one track?

[Dingeling]

I have one track with music and another with a small child singing along. There is a segment were the child starts singing the chorus, but because it sings slower than the music, the music finishes before the child does. I want to compress or speed up (not cut) the child track so that it ends at the same time as the music. How do I do this?
(I realise that this will raise the pitch of the childs voice a little, but that's ok).

[steve]

Select the part that you want to speed up and then apply one of the following effects (all in the Effect menu).

Change Speed. This literally speeds up (or slows down) the selection, affecting both the tempo and the speed. The sound quality is virtually unaffected, though speeding up too much will make the voice sound like a cartoon chipmunk. http://manual.audacityteam.org/man/Change_Speed

Change Tempo. This attempts to change the tempo without changing the pitch by using a form of "time stretching". This technique is inexact and will cause some loss of sound quality and the processed selection may have a brief pause at the start/end of the selection. http://manual.audacityteam.org/man/Change_Tempo

Sliding Time Scale / Pitch Shift... This effect allows you to make a continuous change to the tempo and/or pitch of a selection by choosing initial and/or final change values. By setting the initial and final values differently you can make the audio gradually speed up or slow down. Setting the initial and final values the same will change the tempo by the same amount throughout the selection. This effect uses a more complex algorithm than the Change Tempo effect and usually produces higher quality than the Change Tempo effect, though processing can be quite slow. http://manual.audacityteam.org/man/Effe ... itch_Shift...

[Dingeling]

Fantastic; thank you Steve!