If you google information about longest running bands, there seem to be conflicting accounts, like U2, ZZ Top, Rolling Stones, etc, which depend on the criteria used (no gaps, same members, etc). These tend to focus on rock bands, but surely there are other music genres, or even soloists (e.g. Dave Bartholomew or Bob Dylan), who might have lasted longer, or are still playing music.
So, I guess to properly answer this, we need some precise definitions. I propose:
Who is the (i) singer and (ii) band that:
- was active for the longest period, without interruptions, but not necessarily with the original members
- was active for the longest period, without interruptions, with the same original members
- is still active for the longest period, without interruptions, but not necessarily with the original members
- is still active for the longest period, without interruptions, with the same original members
It might be worth mentioning those who fit the above, albeit having had some interruption in their career. Yet, for the moment the above is enough.