Who’d have thought, when klezmer re-emerged in 1970s, it would become a revival?

Not Hankus Netsky, who founded the Klezmer Conservatory Band in Boston as one of three bands looking back to the Eastern European Jewish instrumental tradition rooted in centuries of Yiddish culture, especially wedding celebration.

“When we started there were about five bands in the world. To everyone’s surprise, there was a revival,” says Netsky, whose KCB will be among more than a half-dozen world-class acts at the fifth Yidstock Festival July 14-17 at the National Yiddish Book Center.

In addition to KCB, marking more than 35 years since its formation out of the New England Conservatory, Yidstock 2016 features a 30th anniversary concert Saturday night with The Klezmatics, as well as performances by British-Yiddish performers Merlin and Polina Shepherd.

Such a range of talent would have been unthinkable when busking Berkeley flutist Lev Feldman and fiddler David Skuse teamed up in 1976 with clarinetist David Julian Gray to form the pioneering Klezmorim.

By 1981, when Netsky’s KCB released its first album the band hailed it as “Yiddishe Renaissance.”

An older generation then recalled growing up with klezmer, and the younger generation was excited, Netsky recalled, “because they remembered all this music that was about their actual roots. It was a very intergenerational revival, and we were doing it without the nostalgic ‘slipcovers’ … so it sounded fresh and attracted a whole new audience.”

Without words, the instrumental music was accessible and evocative because there were no words … and yet bands explained, fostering the Yiddish Book Center’s own revival of the language.

“We translated it, we put things in context, and we did things the nostalgia people never did, because they didn’t need to because it was nostalgia. But we explained.”

With help from Kapelye founder Henry Sapoznik’s Klezcamp in 1985, the revival by about 1990 had become “a point of departure for people to do various creative adventures,” says Netsky.

The Klezmatics’ 1986 founding and film scores by that rock-star-like group as well as KCB.

“Various things started happening: reggae fusions, things of every possible kind,” Netsky said, “with the European scene opening in the 1990s. That changes a lot, because all of us go through the 1980s assuming we’d never see a European klezmer.”

Also in the 1990s, high-profile musicians like classical Itzhak Perlman, experimentalist John Zorn, and Don Byron, “all kind of did their own things” to spread klezmer’s popularity, like cream cheese shmored on a bagel..

Along the way, the music’s “changed and grown,” as all traditions must do,” said Netsky.

Today, “I think we’re on the verge of a huge Jewish ethnic revival, because it’s what young people want. The first round was the Jewish part of the folk revival. For me, I’d heard Jewish music all my life, but none of it spoke to me before I heard … older performers’ (recordings) very directly, in an immigrant sort of language, rather than some sort of heavily reprocessed, watered-down version.”

Yidstock

Yidstock, with the KCB, Klezmatics and more, brings it all together.

“It’s kind of like greatest hits of the first five years, plus new things we haven’t had before,” said festival organizer Seth Rogovoy, who wrote “The Essential Klezmer,” and will give a historical talk, “Rockin’ the Shtetl,” Friday at 1 p.m.

The festival, which last year drew about 1,300 people, is bringing together this year “more of everything than we’ve ever had” — concerts, workshops and talks by leading klezmer instrumentalists and Yiddish singers. Some of their performances over the four days will present combinations that have never been seen before, Rogovoy said.

Those mix-and-match moments, testing the performers’ unique approaches, affinities and differences, has played out in different ways, like the first-of-its-kind “brass khazones” duo concert a few years back in which trumpeters Frank London of the Klematics played cantorial duo music with trumpeter Steve Bernstein.

“It had never been done before, anywhere,” said Rogovoy.

This year, London, who played a concert last year with singer Eleanor Reissa, will be teamed up with English clarinetist Merlin Shepherd and the Merlin Shepherd Group in a Sunday 3 p.m. concert. London, who will perform with the Klezmatics and who originally played with Netsky’s original KCB 35 years ago, will also appear as one of three special guests at the Klezmer Conservatory’s opening-night concert Thursday along with Reissa and Klezmatics vocalist Lorin Sklamberg.

Sklamberg will team up with the Shepherds for a 5:30 p.m. concert on Friday.

The Eleanor Reissa Trio will perform a Friday afternoon concert, and Sunday noon there’s Paul Shapiro’s “Ribs and Brisket Revue” before Sunday evening’s Yidstock All-Stars finale — a musical tribute to Sholem Aleichem, marking the centennial of the great Yiddish author’s death with recreation of Cab Calloway’s klezmer arrangements of “Fiddler on the Roof” tunes.

There are also workshops: a choral workshop in Yiddish song with Polina Shepherd at 3 p.m. Thursday, a Friday 11 a.m. workshop in Yiddish dance with Steve Weintraub, and a Friday 1 p.m. workshop in niggunim — wordless Yiddish song.

As the schedule linked to below shows — there’s plenty more.

On the Web: www.yiddishbookcenter.org/yidstock