Possible Clues:

• The first words of the answers to starred clues are a mnemonic for this musical symbol's staff lines
• Staff opening?
• Right-handed key
• Usual indicator of pitch
• Staff opening
• Indicator of pitch having threefold split almost
• Note-clarifying symbol
• Notes with this: 3x150F
• Musical character felt laid back about awkward celeb on right
• Music character around clubs left rebel in Dire Straits