Changing pitch of a song

[Hypnos]

So, say I wanted to cover a high song with a low-pitched male, so I pitch down the song in UTAU. How would I pitch the instrumental to the same pitch?

 

[Halo]

Well, honestly, you should just pitch down the UST 12 steps so it's in the same key. This works for most male voices.
BUT if it really doesn't work in that key, most mixing software have pitch changing effects in them. Simply apply one of those to the karaoke, the same amount of semitones down as you put the UST down, and using the "algorithm" or settings that makes it the least... artifact-y.

Good luck. I suggest using one of the better mixing programs if you need to do this; minimum REAPER, FL studio, Adobe Audition might work, as might Mixcraft but I don't know about them so much. Make sure you preserve the speed, in any case.