Related Clues:

• Aware, with 'in'
• Attuned
• Nervous, with 'up'
• Tensed, with 'up'
• Atwitter, with 'up'
• Excited, with 'up'
• Worked (up)
• Tense (with ''up'')
• Like a piano
• Tense (with "up")
• -- up (excited)
• Typed in
• Regulated the pitch
• Tense, with 'up'
• Scratched, as the paint on a car