i play guitar and do vocals at the same time and don't have much trouble with it, just base your vocal rhythm's off of the rhythm of the music and practice practice practice
Well, here's the thing. The album is done and we're about to send it out en masse to the labels. The drummer played every instrument including vocals and now he's gotta play drums live. We can't find a singer so I've decided to pull double duty on guitar and drums.
If the guitar rhythms were easy chug-a-chug riffs like Metallica or something, it wouldn't be a problem. However, most of the guitar rhythms are in a different meter than the vocals AND drums sometimes, so it's even more difficult.
I'm not comparing us to Meshuggah, but think of it like trying to play and sing a song from Meshuggah. Not quite as complicated, but odd time and polyrhythms are in there and it's fucking tough sometimes to play and sing.