Possible Clues:

• 1970 #1 hit with the lyric 'Easy as ...'
• Network that tried a 'Charlie's Angels' reboot
• Letters that are the epitome of ease
• *Jackson 5, 1970
• It succeeded 'Let It Be' as Billboard's #1 single
• Start of a learning song
• Big Three member
• Alphabet section
• See 37-Across
• 'This Week' airer