Mark Mueller is an American songwriter and singer. A two-time winner of the ASCAP Pop Award for writing one of the Most Performed Songs of the year, he has had three Billboard Hot 100 Top Ten singles and one #1 Adult Contemporary hit. He co-wrote the hits "Crush" by Jennifer Paige and "That's What Love Is For" by Amy Grant and wrote both words and music for the Top 10 hit "Nothin' At All" by Heart. Songs he has written have been featured on RIAA-certified gold and platinum records in four consecutive decades: the 1980s, 1990s, 2000s and 2010s; and on the Billboard Top 10 charts for 30 years.