Possible Clues:

• Tremolo's kin
• Violin effect
• Pulsating musical effect
• Rapid variation in pitch
• Fiddle not half inspiring difficult child — that's the effect of music!
• First name in 'The Godfather'
• Rapid pitch variation
• Current cup holder to follow victory: change pitch with this?
• One is bound to change pitch with this sign from childish type inside Number 10
• Rapid alternation in pitch