The Monday evening concert series on the Rooftop at the G has been happening since, what, fall? Summer? It’s been a while now. Providence’s only rooftop bar is frequently on my mind during the hot months and not on my mind at all the rest of the year, which means I keep forgetting to check it out (even though I spend a lot of time hemming and hawing that this city has the most joyless after work scene). But all manner of local musicians have played no-cover shows on the roof. (No cover as in you don’t pay anything at the door. The roof itself is covered from the elements, and apparently very cozy.) This week it’s the improvised electronics of Julia.