Complex sentence: In the summer of 2012, Kelli joined as guitarist for John Waite, who sang for the Babys and Bad English and also had a No.1 solo single with "Missing You" in 1984.
Split into simpler sentences: In the summer of 2012, Kelli joined as guitarist for John Waite, who sang for the Babys and Bad English. John also had a No.1 solo single with "Missing You" in 1984.