Possible Clues:

• Played expressively within the tempo, in music
• Deviation from tempo (music), or tuba (anag.)
• Departure from strict tempo; bar out (anag.)
• Right shaky about distorted rhythm
• Flexible tempo and spirit shortened, as is conductor's stick
• Arrangement for tabour played with freedom
• Tabour (anag.)
• Rap, in our strange distorted rhythm
• Run about wildly, not in regular time
• Rhythmic flexibility presents difficulty at start of opera