Hi Steve,
I sing lead and harmony vocals, and I play lead and
rythym/chording/background styles of harmonica. More often than not, I
end up using a vocal microphone to play harmonica through as well.
This is not the most comfortable situation as it is a natural harmonica
handling technique to cup the microphone while playing. This will
normally spell disaster in the form of huge amounts of feedback being
generated if a cardiod type vocal mic is used. Because cardiod type
microphones (cardiod, super cardiod, hyper cardiod, et al) are the most
common type of microphones in stage use, this will normally be a "bad
practice" to cup the hands around the microphone. Avoid this harmonica
handling technique and you will eliminate 90% of the potential sound
issues.
Approach the microphone with your hands holding the harmonica as you
would if there was no microphone in use. Open your hands a little
toward the windscreen of the microphone and find a distance and hand
opening that will provide a suitable volume level for the harmonica.
Do not allow your hands to embrace the sides of the windscreen! That's
when the feedback trouble begins.
My vocal is particularly strong and loud. When playing the harmonica,
I find that if I open my hands a little and keep a distance of around 1
inch away from the windscreen, I then have a workable balance between
the my vocal and my harmonica. Vary the size of your hand opening and
the amount of wind pressure on the harmonica reeds to regulate the tone
and volume of your harmonica. It takes practice, and a decent monitor
feed to learn how to balance, but it can be accomplished if you work it
a bit.
I also use a harmonica brace when playing guitar or piano. I find that
I need to get this a little closer to the microphone as I cannot
generate nearly as much pressure on the harmonica reeds while using the
brace. Usually end up with the harmonica pretty close to touching the
windscreen most of the time using a brace.
The best setup is using separate microphones, with one mic being my
vintage green bullet for ripping Chicago style electric blues or rock
styles. This mic has a separate volume control on the mic, plus it
colours the sound with compression and distortion that is desirable for
electric blues. These types of "harmonica microphones" are low fi, and
all about tone. They mostly can be held cupped without nearly the
feedback problems of vocal mics.
There are however, some selections that are much better played cleanly
through a vocal microphone. Listen to Charlie Musselwhite or Carlos
del Junco for a good spectrum of clean blues, rock, country, jazz,
etc... played through a vocal microphone.
So yeah, you can work this together on the same vocal mic. It's been
done to death by myself and many others. It will even work with an
SM58 if that's all you've got. Hell, I saw Charlie Musselwhite using
an SM58 while playing with B.B. King and it sounded great. There are
better microphones than the SM58, but a good performer will always find
a way to transcend equipment limitations.
Cheers,
Skeeter (aka "Harpmeister")