What a fun evening in Hoboken last night. The usual cast of characters — Batman, Hula Hoop lady, Naked Cowgirl — was in force as was the smell of sizzling sausage and peppers, but local Frank Raia’s annual birthday bash on the Hudson River waterfront had a most pleasant surprise — Alter Ego presents Decades.

This is what its Web site calls a “musical showcase.” It was essentially a cover band that performs — singing and dancing — music of the 70s, 80s and 90s (although “Lady Gaga” made an outstanding appearance to represent the 2000s). It was hours of one great song after another, all choregraphed and costumed to mimic the real thing.

I couldn’t stop singing and laughing with friends Susan and Kathi. What a trip down memory lane. When’s the last time you sang “Oh Mickey you’re so fine, you’re so fine you blow my mind. Hey Mickey” in public? (I know, why would you want to? It was a blast, trust me). Bon Jovi, AC/DC, Michael Jackson, Madonna, Bryan Adams, Donna Summer. Crowd pleasing tunes like “Lady Marmalade,” “Disco Inferno” and “Girls Just Wanna Have Fun.”

Made me regress, in the best possible way.

In between, of course, there was a guy doing Sinatra. Sitting next to us was a couple that looked like it stepped out of a bad mafia movie. Honestly, it made the “Real Housewives of New Jersey” look tame. She had very long bleached blonde hair and was wearing jeans, a filmy hot pink top, rhinestones everywhere, shoes that appeared to be Candies with a whole pink glittery thing going on, and pink sunglasses well into the dark of night. He was all in black with white sneakers and a gold chain around his neck. A caricature if I’ve ever seen one.

Did I mention the Manhattan skyline as backdrop? This is where I live. And I wouldn’t change a thing.