A while back I wrote about rock musician John Mellencamp, who decided that his band had gotten into a rut. As a challenge, he required each member, including himself, to learn a new instrument that would be featured on songs for the next album. That album explored an entirely new sound for the band and became one of their most popular. The band talked about what they wanted that album to sound like, departed from their usual music to make it happen, and extended their success.