My early musical training was on trumpet. I could play anything that was written and was first chair in the Oklahoma All-State Band as a sophomore in high school. The good news is that the band director had sense enough to encourage me to also play "off the charts" and to experiment with other instruments as well.
By the time I got out of college I could play bass, guitar and drums fairly well, in addition to trumpet.
Band back home needed an organ player so I bought one and literally taught myself on stage. I was able to do that because the band director had instilled such a good background in music theory.
I'll never be anywhere close to a Russ Lay level, but I can appreciate what he is saying about enjoying all types of music.
The reason I do a lot of country and vintage rock and roll these days is that's what they pay me to do!