From Seventh String Software:
Transcribe is a specialized player program to help musicians figure out music from recordings. Transcribe! can slow down the music without changing its pitch, analyse chords, and play video if present. It supports footpedals, loops, markers, textual annotations and much more.
Simple to use, works great for transcribing melodies. You can speed up the melody to 150% of the original speed or slow it down to less than 5% of the original speed. You can also remove instruments from the song to let you concentrate on the melody or instrument you are trying to hear. It's not hard to use, but it does require that you read the instructions and experiment and play around with the software. The first day I downloaded this software I transcribed a Miles Davis solo. Transcribe is a tool you'll use a lot regardless of musical ability.