Ya'll be whatever yas wanna be up there, I don't mind watching. If you play well with enthusiasm, who cares (oh yeah, obviously some folks do). Heck ya'll, I'm freaking 61, ponytail down my back, bushy moustache and beard, and have ridden my Harley to a gig before and played in my riding clothes, including leather vest with colors, do-rag, riding boots, etc. Does that mean I don't care about my playing. H*** NO!!! I played my arse off that night. Hey, I'm a serious musician, have a degree in music, and have played professionally full-time. Recently when we had a classic rock gig going for awhile, we each wore whatever we wanted. I was the jeans and t-shirt guy, another was the jeans and collared shirt guy, another was slacks and silk shirt guy, the drummer was jeans and loose shirts. We didn't even specify. Be whoever you want. I was 60. When I untied my hair to play Woodstock, even the young crowd went nuts. Heh, heh.
But then, I wear a tux to weddings because it's appropriate (see I DO care), or slacks and a nice shirt to other gigs because it's also appropriate. My most recent band wants to all wear the same shirts. Whatever. That's not my style, but I like the gig very much, so...
But you can bet yer socks I"M SERIOUS alright!