Possible Clues:

• Former boy band, 'N___
• Out of __: discordant
• Harmony, so to speak
• Relationship when things occur at the same time
• iPad-to-iMac activity
• In ___ (singing together)
• New York City in a whirl after dollar provides short form of perfect harmony
• Does this mean Crosby, Stills, Nash and Young reformed for harmony?
• Together, after "in"
• Audible drop in harmony