....

To me, I would agree that, e.g. "Fred Fargle with orchestra" should go under just "Fred Fargle", because it's an unspecified orchestra - the equivalent of a studio pick-up group. However, "Fred Fargle And His Orchestra" is very specific; it's His orchestra rather than anyone's or no-one's.

In this as in anything else, there will be inconsistencies, but we can link where necessary.

Here's my mea culpa at the end of this: the other night I reverted most of the Harry James ones mentioned in Dr.D's opening post to Harry James And His Orchestra in line with that - for want of a better word - reasoning. Feel free to change them back if you think it matters; I'll be a bit more circumspect about it in future.