[quote:3ezag7e9]pick up a guitar or keyboard and find the right key trying all of em. there are only 8 
[/quote:3ezag7e9]
i agree with this one(except the 8 keys). Most songs are in major or minor. (There are some weird scales out their if you really want to get into the amount of different keys and chord variations). And trying to find every single note that will sound good will take a little bit of time.
If im trying to play note for note along with the vocals then i might use software to help me out. I use an autotune on the vocals which displays the keys that are being sung/played then take the autotune out after i have it figured out
….and i just realized how old this post was after writing all that 
, hopefully the autotune info is useful to someone
