* Some people cultivate nice gardens in their front yards to beautify the neighborhood for all who pass by. In Beacon Hill they keep them concealed behind walls and only let common street trash like you in for the Hidden Gardens Tour one day a year. Today is that day! Some conversation topics for hob-nobbing with old-money elites: how the city really went downhill ever since they filled in the Back Bay; why liquor licenses should be limited to private social clubs; and what does the T even cost these days, a dollar? 5.15. 9a. $35-45 

* Sure, that Pink Floyd poster with the album covers tattooed on naked ladies is pretty sweet, but you’re a grown-up now and it’s time to upgrade your rock and roll-themed art collection. Peter Desimone’s Portraits of Rock series will be on display all month at Bukowski’s in Cambridge, and the artist stops by tonight for a meet and greet. He’ll also have plenty of $25 framed prints available for purchase — cheaper than those Beacon Hill bastards charge you just to look at their gardens. Tulips never melted anyone’s face with a guitar solo. 5.15. 7p. FREE

* Remember those street pianos that mysteriously appeared across the city last year? You stumbled across one and played “Heart and Soul” with your date and for one brilliant moment your life felt like a romantic comedy. The folks behind those pianos, the Celebrity Series of Boston, return with this weekend’s 200-person choreographed dance extravaganza in Copley Square, Le Grand Continental (or because we’re Bruins fans and hate all things Canadian, “The Large Continental.”) Check out performances Friday and Saturday nights and Sunday afternoon. 5.16 to 5.18. 8:30p and 3p. FREE

* This is the one we really don’t want to see rained out: PorchFest a.k.a. Keep Somerville Weird Day a.k.a. the greatest and most wonderful day of the year. Bands set up on porches all over the city and play for free, and you wander around, and talk about how great it is, and maybe stop at your friend’s place to add some whiskey to your iced coffees, but not too much because this is a family-friendly event. Right now my phone’s predicting a 90% chance of rain for Saturday, and a 30% chance for the rain date on Sunday. You are my sunshine, my only sunshine. You make me happyyyyy… 5.17. 12p. FREE

* Ain’t no party like a St. Stanislaus Day Party ‘cuz a St. Stanislaus Day Party has live polka and that is uncommon in this region. This is actually a decent PorchFest stand-in for Saturday: It’s in Somerville, it’s indoors, there’s live music, and it’s fun for all ages — but more fun for ages 21 and up, because beer. The polka stylings of Al Janik’s Plastyczny Ser Orkestra (roughly translated as Plastic Cheese Band) and special guests headline the celebration to honor the patron saint of Poland. 5.17. 6p. $10

* At Saturday’s Burger Slam, chefs from The Haven, Gaslight, Sycamore, Grass Fed and the MFA duke it out for a good cause: briefly satiating the alien that lives in your tummy and craves meat and makes weird noises when he doesn’t get it. Just kidding, it’s really a benefit for the JP Manning School. 5.17. 6:30p. $25

* Puppy party! Puppy party! The annual som|dog Spring Fling in Union Square is a pretty big deal for pups, because they get to meet dogs from all over Somerville. It’s like when you were in high school and went to the mall to meet girls from other schools, except you probably never met someone and thought, hey, I’ve smelled your pee before. 5.18. 10a. FREE

* Across four downtown venues, the Boston Environmental Film Festival brings the latest films on current environmental successes, struggles, actions and animations. Heh. Funny how the environmental film festival just happens to take place on a weekend when a bunch of other cool events will probably get rained out and you pretty much have to go to the movies. Fuck you, environment. 5.18. 11a. $10