John,
In your fairly accurate description there you used several adjectives,
good, folk, 'serious', current, old-man, jazz, good again. I got a pretty 'good' idea of what you had listened to, for which you could perhaps have employed words like 'fusion', 'cross-over', I don't know, I'm not an expert, but the point I'm making here is that many many people (I nearly used the word 'folk' here) use the adjective folk in a similar way and it simply helps to give them a rough idea of what someone might have been listening to, as opposed, say, to jazz, or classical or even 'serious'.