Possible Clues:

• "I've Gotta __": 1969 hit
• "Let It __": Everly Brothers hit
• 'Let It --' (1960 song)
• Everlys hit, "Let It ___"
• "It's not easy to __": Five for Fighting lyric
• "I've Gotta __": Sammy Davis Jr. hit
• Everlys' hit, 'Let It --'
• Egotistical Keith Urban song "Who Wouldn't Wanna ___"
• Everlys' song, 'Let It --'
• 'I've Gotta ___' (Sammy Davis Jr. hit)