Thats true Switchgrass but not why the pitch changes.
The 488 only records and plays at one speed which is faster than any standard stereo or tape deck will play at.
This gives the 488 better recording quality because the faster the tape speed, the better the recording.......but the more tape is used and is one reason it costs more to record better.
You need to mix down your 488 recordings to a standard speed 2 track tape deck in order to be able to hear it correctly.
-mike