I had a similar thing happen to me as I`m an old rocker who was gigging in the 60/70s. The first thing to try is fast forward (both ways) several times. If that doesn`t work (as it didn`t for me) I approached the local music shop who sent me to a small recording studio where they had a variable speed player. They produced a CD from my tapes and it cost me £20
Donny
May 2008