Possible Clues:

• 'Resume speed,' musically
• ''Resume speed,'' on a score
• At the original speed, in music
• Say to the Post Office what was said to the Guards as fast as before
• At the original speed, in scores
• Back up to speed, musically
• Accelerando undoer
• 'Resume the original speed'
• 'Resume speed,' to a musician
• Resuming the previous speed, in music