[78-L] Challenging advice

[Julian Vein]

 From a Challenge sleeve:

"Proper Playing Speed
All Challenge Records should be played at a speed of 80 revolutions per 
minute. If they are played faster than this, the pitch will be higher 
than the original music. If played slower, the pitch will be lower....

To test the speed, slip a piece of paper under the record, allowing it 
to project out far enough so it can lightly brush your hand as the 
turntable revolves. Now with watch in one hand and the other hand placed 
whether the paper can touch it each time it comes around, count the 
revolutions. The paper touching your hand at each revolution makes it 
easy to count..."

      Julian Vein