Some people learn how to play an instrument and then spend the rest of their lives attempting to perfect their technique.

That’s not for Charlie Rosen. The New York City man is more interested in perfecting the technique of learning instruments – 70 of them and counting.

“You start to treat them as families of the same instrument. Once you learn how to play one instrument that you blow into, it’s really just a matter of translating those skills to a slightly different one,” he told CTV News Channel on Monday.

“Guitars, mandolins, ukuleles -- I call them ‘things with necks’ -- once you learn how to play a thing with a neck, you move to the next thing with the neck.”

Rosen can handle things with necks, sure, but he also knows his way around the tuba and the tambourine and the theremin – an instrument capable of producing the eerie sounds you might associate with old sci-fi flicks.

“It’s one of the only instruments that you play without physically touching it,” he said.

“It’s a pretty unusual and exotic instrument, but there’s a thriving scene for it – and I’m happy to be a part of it.”

Rosen also demonstrated the melodica, which he described as a harmonica-like wind instrument equipped with a keyboard.

Being able to play so many unorthodox instruments isn’t just a gimmick for Rosen. He finds it gives him a wider array of tools to call on for his work composing and arranging pieces.

“It’s like having a palette full of paint – and the more colours you have on that palette, the more you can blend them together to make new colours,” he said.

Rosen has composed, orchestrated and performed music for a number of Broadway and off-Broadway plays, but his resume also includes more eclectic roles, including as the bandleader of a band that performs video game music.

Most recently, he orchestrated the score for “Be More Chill,” which opened on Broadway last month. It tells the story of Jeremy, a high school student who has trouble fitting in and tries to take “the easy way out” by getting a brain implant that tells him what to say to be considered cool.

If the plot description doesn’t suggest on its own that the implant may not be able to offer exactly what it promises, the musical cues certainly do. Whenever Jeremy comes into contact with the implant, the audience hears what Rosen describes as “spooky sci-fi noises” – courtesy of a theremin.