Hi forum, I recorded a keyboard track many years ago, and now I noticed we tracked it at 100bpm with the metronome off because it wasn't in sync, but now many years later I'm trying to add tracks to the song but the tempo is really supposed to be 60bpm. Is there a way to change it to the right tempo? I tried dumping the midi track into a new session already set at 60bpm, but it sounds way slower than it's supposed to be. Thanks in advance!!!

I would create a tempo map. Try bouncing to audio and use the Audio to create a tempo map. Worth a try before you start hand-editing.
 
https://www.youtube.com/watch?v=M_SKmr_07Is
 
 

But, wouldn't setting the changing the tempo to 60 BPM make the MIDI file play slower anyway. 

Or do you wish to change the designated tempo of the MIDI but have it playing at the same speed?

If that is the case, what you can do is load the MIDI file into Sonar normally.  Then change the tempo to 60.  At this point the some will play 0.6 times slower.  To get the MIDI playing back at its original speed, select all MIDI tracks, then Process | Length, make sure Start times and Durations are ticked and enter 60%.  That will get the MIDI to play at the original speed but change your tempo will remain at 60 BPM.

Bear in mind, if you do this, then the notes will likely no longer be aligned to measures.

Thanks Guys, I tried changing the Process length to 60% like you said, and it works! That's the good news, the bad news is after listening to it, the playing was off, so I might have to get my keyboardist back in here to re-record it, cause I think he can re play it much easier than it would be for me to fix all the midi information. But thanks again guys!!!

Just open it in the Piano roll view and either move notes or quantize.
Midi is easy to adjust tempo. Once it is in the timeline, simply change the project tempo.

If by "off" you mean A) it doesn't hit all the beats at a constant 60 BPM, that's fixable. If "off" means B) it doesn't sound any good, that's a candidate for replay.
 
If A), the thing to do is use "set measure-beat at now" as an easy way to make appropriate small adjustments to the tempo to match the playing.
 
 

If MIDI track by itself is in sync with other (audio) tracks (f.e. if everything was recorded without click but in sync) and the only thing you need is to apply new (not constant) project tempo map (extracted from other tracks or rendered MIDI) to MIDI tracks, you can use this: http://www.azslow.com/index.php/topic,286.0.html (search for "Apply tempo map").

<p>Thanks Guys, I tried changing the Process length to 60% like you said, and it works! That's the good news, the bad news is after listening to it, the playing was off, so I might have to get my keyboardist back in here to re-record it, cause I think he can re play it much easier than it would be for me to fix all the midi information. But thanks again guys!!!</p>

Came across this video after reading the new comments in this thread.  This looks like what I need, but I feel my keyboardist would say tracking it over would be easier, but I'll check it out for future projects if needed. Thanks again forum...
https://www.youtube.com/watch?v=FPeRp7092-c

If all you need is stretch the midi file to adjust to new tempo, then hold Ctrl + Shift and click & drag the lower-right end of the midi clip, in arrangement view.