Related Clues:

• Sing like a sparrow
• Composer's embellishment
• Vibrating musical effect
• Sing till Queen enters
• Unevenness in pitch? English right back has second look
• Musical shake? Lot more wobbly!
• Swallow sound
• Note from a bird
• Cabaret singer ends poorly in quaver
• Fluctuation in pitch
• Bird's warbling sound
• Vocal quaver
• Vocalist's warble
• Quivering musical effect
• Vibrating noise in shaky Metro line that’s old