Possible Clues:

• Note matching pattern of radar
• Note car on motorway
• Musical note equivalent to half a semibreve
• Note sent back unaltered
• Note passed from either side
• Note sixties-style skirt on maiden
• Palindromic music note
• A note in music, half as long as a semi-breve- it's a palindrome
• Note a mere drop of medicine
• Short note