In the long history of musical instruments, the very old -- say a Stradivarius violin -- are revered, having stood the test of time.

But in the more recent history of electronic music, instruments are rapidly supplanted by the next new thing.

Now, there's a growing group of musicians who are returning to old analog keyboards, sometimes refurbishing instruments older than they are.

In his Fishtown showroom, guitar maker Chris DiPinto rummages around a collection of vintage synthesizers and organs.

"This is a Hammond home organ, cheesy drum machine, this is a Crumar, total '70s sound ... ," he points out.

Over the course of 20 years, DiPinto has seen keyboard fashions come and go. Now, what used to be bygone relics have become coveted treasures for a musical movement. Across several styles, players are trotting out old Arps, Farfisas and, of course, the most famous analog synthesizer, Moogs.

When Robert Moog created his first synthesizers, they were both lauded and feared for the wide range of sounds they could make. But they soon gained a reputation for being temperamental and difficult to play. Most musicians didn't need or want to tailor every sound their instrument made. So when digital synthesizers came along in the 1980s, with fewer, fixed sounds, the analog siblings were left behind.

"Things got a lot more digital sounding, and people wanted to sound like bands they heard on the radio and they were using things like a Yamaha DX7, which gives you a real crystal-clear digital sound," says DiPinto.

Warming to the old keyboards

With that reputation for crankiness, what's drawing musicians back to the old keyboards?

"It's just the warmth," says Jimmy LaValle.

LaValle and his group, The Album Leaf, use Moogs to craft a distinctive sound.

"There's a lot of older synths that I think just have a tone to them and they're just really powerful and they're really hands-on," he says. "There's something more immediate. You can connect easier to that kind of setting as opposed to computers."

Philadelphia-based music producer Gino Wong agrees.

"So you could say that there's a more perfect human interface with the analog instruments. And you could tweak the sound and tailor the sound how you felt at that particular moment.

"And that's why young musicians like to use them," Wong says. "They can get to what they're feeling very quickly. And they also look cool."

Many see this revival as part of a broader "do it yourself" trend.

There's definitely a DIY movement," Wong says. "Knowing how things work is really important, and using things and restoring things, fixing it, using it, wearing it out. People have forgotten how to make things.

"When you're confronted with a 25-year-old synthesizer, you have to go and find a capacitor or a transistor that's gone wonky and you have to repair it," he says. "So you have to know how it works and how to fix it."

Vintage instruments mean special challenges

But as collectors of anything vintage will tell you, there are special challenges when you're collecting something that's not being made anymore.

"We have to go and look for vintage transistors and integrated circuits and it's very difficult to find the parts," Wong says. "A Moog synthesizer from 1969, when it's gone, it's gone."

Chris DiPinto thinks all the challenges -- the scarcity of the parts and the quirkiness of the instruments -- somehow add to the creative process.

"Sometimes you need the original keyboard, you need all its flaws and all its mistakes to get the beauty of it and be inspired to create," he says.

For his part, LaValle says he's basically "kind of a purist when it comes to that. That's why I choose to use Moogs."

Jimmy LaValle and The Album Leaf have a new EP called "Forward - Return." They'll be bringing their vintage synths to the Trocadero for a show on Saturday.