A 68 Bassman will work as a harp amp (I use one) but I wouldn't recommend it as
a first choice. For the money you'd be better off buying a silver face
Princeton or even a Blues Junior. If you do use the Bassman don't use the
bright switch, roll the treble way down.You'll get a very clean sound as it's
so loud you'll never turn it up past 2.Feeds back like crazy at 3.
If you need one amp for keys and harp, the Bassman works well.
I bought my Bassman head for $75.00 a million years ago. You might want to think
about buying a harp commander and a used keyboard amp-Roland or Peavy. You
could get a real loud light trouble free rig for $600.00.