Opera where you least expect it: Roslindale Square

Amen to the substation buildout including a venue for live music!

There's a bit more already than just the patio scene you mentioned, though. There's live music almost every Saturday at the Farmer's market, and during the summer there's a concert series in Adam's park (not this summer during the reno, obvs). Suya Joint hosts live music events as well. And live music is part of many of the events hosted by the neighborhood churches. (I think even the original (ie not the last) owners of the Rosi Cafe hosted some small performances).

But I think the village will have to get significantly busier before it makes sense for anyone to try to regularly busk in the actual park. I could see someone trying it nearby at the bus stops at Washington/Poplar or in front of the community center (at least when the weather is good).

Iirc, a couple years ago Saxophone-guy made his way through the area, but I don't think there was enough foot traffic to sustain him - I think there wasn't enough even in the middle of WRox, although he gave it a go there.