Possible Clues:

• 'It's tough that it's no good for music (3,7)'
• 'Unluckily, no good for anything 15 across (3,7)'
• It's tough that it's no good for music
• 'Unluckily, no good for music (3,7)'
• 'No luck, no good for music (3,7)'
• How unlucky for it to be no good musically
• No luck if it's no good for music
• Unluckily, no good for music
• No good for notes, no good for luck
• Your luck's not in if this is of no benefit for music