I think as pro has pointed out it really matters what type of gigs you want to do. For some here it is necessary to sing for others not.

My early musical journey was all about vocals. The last 7/8 years of the journey though I played Vibes in a Latin Jazz band without any vocals. I've always played the clubs and larger gigs though, like concerts in the park Cinco De Mayo celebrations and the like.
Terry

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jam on,
Terry http://imjazzed.homestead.com/Index.html