Sonar 8.5 Producer

Tempo change is a term of art for MIDI and Sonar and it means that a setting within the project has changed. I assume that is not what you mean, but rather in the musical sense that the project plays slower. Key change is a musical term of art and it means that the scale has changed but that the pitch/intonation of the notes has not. I assume that is not what you mean, but in the physical sense that the pitch of all the notes has shifted to a lower frequency. Slower and lower in digital audio is a common symptom of a sample rate mismatch-recording at a higher sample rate, playing back at a lower sample rate. If the difference is something like 96 K to 44.1 K, I assume you would have said something other than the key has changed as the distortion would have been dramatic. Usually the problem is between 48 K (ADAT standard) and 44.1 K (CD standard)--your music has changed but it is still recognizable. If you want help to figure out why this happened, you need to provide a detailed account of how you recorded and how you are playing back with special attention to the sample rate settings of any equipment or software you were using. That would be a useful exercise if you do not want this to happen again. If you just want to fix the problem, with a particular wave file, there are ways to do that.