Complex sentence: "Mercy Mercy" is a blues song written by Don Covay and Ronald Dean Miller, and in late 1964 was a hit for Don Covay and the Goodtimers reaching number one on the Cashbox Magazine R&B chart and number thirty-five on the Hot 100.
Split into simpler sentences: Mercy Mercy is a blues song written by Don Covay and Ronald Dean Miller. In late 1964, the song became a hit for Don Covay and the Goodtimers reaching number one on the "Cashbox" R&B chart and number thirty-five on the Billboard Hot 100.