Complex sentence: Ken Mellons was the first artist to record his material, in 1994, but it was not until Blackhawk released "Days of America" in 2002 that Miller had a writing credit for a chart single.
Split into simpler sentences: Ken Mellons was the first artist to record his material, doing so in 1994. It was not until Blackhawk released "Days of America" in 2002 that Miller had a writing credit for a chart single.