Rough Music, by Nadine Sutton

This story is available on Amazon. It is set in the late 70s and its about a country rock band, who were touring in America, and starting to have some commercial success. The 2 lead singers are good friends and they want to make money but also to write good music and make use of their talent. But life on the road is hard going, and they have to spend a lot of time away from their wives and children. They find it difficult to remain faithful, and life is stressful at times. They reach a crisis when Jeff, the lead singer, finds his marriage is unravelling.