Music director James Conlon conducts a rehearsal of the Los Angeles Opera in Mozart's ‘Cosi Fan Tutte’ at the Music Center in downtown Los Angeles. (ROBYN BECK/AFP/GETTY IMAGES)

You may not have heard of Hans Gal. But the American conductor Kenneth Woods thinks you should have. Gal was a widely respected and performed composer in the 1920s, but the Nazis drove him out of Germany, and though he continued writing, teaching and composing in Scotland until his death in 1987, his reputation never quite recovered. Elegant, adeptly constructed, and unashamedly tonal, even beautiful, his music hearkens back to a bygone tradition of Viennese late romanticism that wasn’t what the music world thought composers should be writing in the late 20th century. As a result, it fell into such neglect that, when his four symphonies were released on the label Avie in 2011 and 2012, they were all world premiere recordings.

“After years of the family trying to get any of this music recorded,” Woods says, “two orchestras agreed within days of each other.”

These days, getting little-known music recorded is a lot easier than it once was — and a lot more appealing to musicians. Now that it’s easier to make a recording than to play Carnegie Hall and the standard repertory has been recorded to death, more artists are staking out their own niches by championing and recording forgotten composers of past eras: the orchestral music of Alfredo Casella; the complete woodwind quintets of Antonin Reicha.

Making a CD has become tantamount to creating a business card: a self-generated form of self-validation. But for many of the musicians who have plunged into these unfamiliar scores and believe they’ve found treasure, the larger point is to make a mark on posterity. “I really believe in this music,” Woods says of Gal’s work. “I do believe it will enter the repertoire.”

There’s one hitch. Although more music is available on recordings, it sometimes seems that less of it is heard in live performance. This is certainly true in the orchestra world, which continues to rely heavily on Beethoven and Tchaikovsky, make occasional forays into contemporary music, and have little room for forgotten composers. So, while recordings offer a cornucopia of music the likes of which the world has never known, this wealth is not widely reflected in live concerts.

Recovered Voices: 'The Broken Jug' & 'The Dwarf' (Robert Millard/Los Angeles Opera)

“It’s a long slog,” says Joseph Horowitz, the co-founder of Washington’s Post-Classical Ensemble who has long worked as a consultant, adviser, and programmer. Horowitz is an adviser to the “American Classics” series on the record label Naxos, devoted to composers like George Whitefield Chadwick (1854-1931) and George Templeton Strong (1856-1948). But he’s the first to admit that, for all the important rediscovery work the series has done, it’s barely caused a ripple in the American orchestral repertoire. Works like Chadwick’s engaging “Jubilee” or Strong’s “Sintram” symphony — “the only successful American symphony in the grand romantic mode,” Horowitz says — simply don’t get performed. “I think much more should have happened by now,” Horowitz says.

James Conlon, currently the music director of the Los Angeles Opera and the Ravinia Festival in Chicago, is one of the bigger-name conductors to devote himself to little-known repertory. His particular focus is the music of the so-called “degenerate composers” — artists who, like Gal, were proscribed by the Nazis. Conlon repeatedly performs operas and symphonic works by Alexander Zemlinsky, Viktor Ullmann, Franz Schreker and others; from artists like Gal who were in the midst of flourishing careers to young talents who were just getting started, like Gideon Klein, who was 26 when he died at Auschwitz. He’s established a foundation devoted to disseminating information about these artists; he makes a point of bringing the repertoire to young musicians; and he’s started initiatives like the concert series at Ravinia called “Breaking the Silence.” But even he — speaking by phone the morning after playing Schreker and Kurt Weill on a program at Ravinia — sometimes has trouble getting organizations to put it on.

“The challenge and the crisis of economic downturn is that all orchestras, opera companies, recital series get more conservative,” he said. “They’re afraid, they’re afraid, they’re afraid. I can’t tell you how many times I’ve made proposals, to artistic administrators who absolutely want what I want. They come back, ‘Our marketing department is uncomfortable.’ ‘[Audiences] see a name they don’t know, they don’t come.’ Is that true? It probably is true. It’s a very delicate balance, in a time of economic stress, just how far to push it or not.”

Indeed, the surprising thing is less that orchestras are slow to change than that recording labels have changed so dramatically. “Obviously, for record labels, unknown repertory is their life’s blood,” Woods says, stating a fact that would hardly have been “obvious” 20 years ago. The template began to shift as recording sales plummeted and smaller, more specialized labels became ascendant. The poster child for this shift is Naxos, which began 25 years ago as an upstart budget label and has become perhaps the biggest recording company in the business, precisely by focusing on little-known work that wasn’t available anywhere else.

“[About] 2 million hours of music have been written since the 12th, 13th century,” said Naxos’s founder and leader, Klaus Heymann, speaking on Skype last month from his base in Hong Kong. “So far, only about 100,000 hours, unduplicated, has actually been recorded. Even a name composer like C.P.E. Bach is not yet complete” — not everything he wrote has been recorded yet. “There are composers whose names you haven’t heard of who wrote 1000 opus numbers, especially baroque composers.”

Is it all worth hearing, worth recording? “C.P.E. Bach probably hasn’t written any bad music,” Heymann opines. “You probably record 600 CDs, [and get] 30 hours of great music, 50 hours of very good music, and the rest would be good music. That’s how all of these complete projects look. The problem is how to get the orchestras to play this stuff that is not standard repertoire, that doesn’t have a special angle.”

Heymann has been remarkably successful in selling a lot of music nobody has ever heard of, though even Naxos is no longer posting the kinds of sales figures it once did. An orchestra, of course, has “a different set of financial considerations,” points out Nigel Boon, the director of artistic planning for the National Symphony Orchestra. A label can sell a few hundred or thousand copies of a CD over the course of a few months; the NSO, by contrast, tries to create programs that can fill the 2,400 seats of the Kennedy Center Concert Hall two or three times in a given week.

Composer Hans Gal. (Hans Gal Society)

This rules out too much specialized fare. An orchestra seldom devotes an entire evening to a single composer, unless that composer is Beethoven or Bach. “You can’t do a whole program of Dussek,” says Boon. “You can include [a piece by him] if there’s a theme that works, or a big-name artist who says, ‘Dussek is the greatest discovery I’ve ever made.’ ”

As a result, unfamiliar works are isolated events, often linked to particular artists. The Dutch conductor Jaap van Zweden will come to the NSO next April with a lively “Cyrano de Bergerac” overture by the Dutch-born composer-violinist Bernard Wagenaar, a piece van Zweden often brings to orchestras he guest-conducts. Boon cites Liadov’s “Enchanted Lake” and Frank Bridge’s “The Sea,” both of which the NSO did last season, and Zemlinsky’s “Lyric Symphony,” which Christoph Eschenbach conducted in 2011, as examples of less-known repertoire. Eschenbach has also recorded the four symphonies of the French composer Albert Roussel. “We’ll certainly do one or more of the symphonies,” Boon says. But, he says a little ruefully, “We’ve done lots of things once.”

Performers of little-known repertory have to fight the tacit assumption that the work must not have been very good if it was neglected in the first place. In the case of Nazi victims like Gal, there’s an extra moral imperative to help restore the work to its rightful place in the repertory. “I don’t believe that every piece has to be a masterpiece,” says Conlon. “It’s not about that; it’s about feeling the spirit of the time . . . We have assumed through a reductionist view of history there was a single line that went through the Viennese school and ended.” He calls it “a misuse of Darwinism” to assume that the works that have survived are automatically better than the ones that haven’t.

Too, a more varied musical diet is simply more enriching. “I can hear Mozart over and over, conduct it over and over,” Conlon says; “I never get tired of him. Still, people need to hear new things. . . . There’s always more out there. The act of listening to something you don’t know is very different.”

For Woods, the association with Gal has brought wider recognition and a number of glowing reviews. Having recorded the third and fourth symphonies with the ensemble he leads, Stratford-upon-Avon-based Orchestra of the Swan, he’s going back to do the first and second, paired, like the others, with symphonies by Schumann. His next Gal recording, devoted to chamber music, is coming out in September.

He’s also coming to the area this fall for a performance. In November, he’ll conduct the Fairfax Symphony. The program is devoted to a single composer — Ludwig van Beethoven. Want to hear the music of Hans Gal? Buy the recording.