At its shows in Europe and across the United States the 11-piece orchestra La Excelencia is often introduced to audiences as personifying 'salsa from New York.' So it is paradoxical that on its home turf the band's hard, tough sound and fondness for lyrics that address social issues has led traditionalists to regard the group as somehow outside the salsa mainstream. Rather than focus the spotlight on a nattily dressed and groomed lead singer, La Excelencia, which performs Friday at Lincoln Center as part of Midsummer Night Swing, operates as a collective. Instead of writing treacly love songs, as demanded by the salsa romantica style that has been dominant for nearly a quarter-century, the group sings about immigration, discrimination and poverty. In place of synthesizers and strings, La Excelencia emphasizes hard-driving brass and percussion, just like a Fania Records band from salsa's heyday in the 1970s. 'La Excelencia represents something very significant, a return not just to the classic formula of salsa but to the virtues of it,' said Aaron Levinson, a Grammy-winning producer best known for his work with the Spanish Harlem Orchestra. 'It's one thing to bring back the campana and make it sound old school. But that's not all they are doing. The really critical difference is that they are also going back to the more eclectic period when salsa was street music, playing with spirit and integrity and writing socially relevant music again.' The throwback eclecticism of La Excelencia, founded in 2005 by the percussionists Jose Vazquez Cofresi and Julian Silva, extends to its makeup. Band members, who range in age from 26 to 35, are of Puerto Rican, Cuban, Dominican, Colombian, Argentine-Ecuadorean and Japanese descent (with a solitary Anglo trumpet player originally from Florida) and know how to fuse styles without making it apparent. One of La Excelencia's signature songs, 'La Lucha,' or 'The Struggle,' blends Cuban danzon, Puerto Rican bomba and Colombian cumbia. 'It is important for us to feature everybody in the band, and that our songs be for all of Latin America,' said Vazquez, who plays conga. Silva, who plays timbales, added: 'That's why we call it salsa. It's a mixture of everybody's music. Why would you want to limit yourself?' Vazquez and Silva met as teenagers when both were part of a Roman Catholic youth delegation traveling to see Pope John Paul II during his 1993 visit to the United States. Vazquez, 34 and of Puerto Rican descent, was born in Biloxi, Miss., and grew up on the military bases in the South, where his father, an Air Force captain, was stationed. Silva, 32, was born in Cali, Colombia, but 'political and drug violence there,' he said, drove his family to immigrate to Baton Rouge, La., before he was 5. Both were members of Los Calientes del Son, a band that toured the South, playing 'everything from salsa and cumbia to rock, jazz and even country, just to be able to gig,' recalled Vazquez, who has an accounting degree and handles the band's business affairs. But in 2000 they moved to New York and quickly signed a deal to record a salsa CD, only to see that project shelved as the reggaeton boom accelerated, which led to a request, soon granted, to be released from their contract. 'We got tired of the kind of rules that were placed on us because we were salsa,' said Silva, who has a degree in psychology and has worked in cancer research at Mount Sinai Hospital. 'We had to wear uniforms for the cover picture. We had to have the pretty boy singers. They were telling us to write about this and not about that, to sing about love and not protest, to cut our hair, look sharp and sing to the women. Jose and I just got fed up with it, and so we told the record label: 'You know what? We're out, we're done, we don't want to be part of this.'' On its own Handle With Care label La Excelencia has released two CDs whose titles give a sense of the group's philosophy: 'Salsa con Conciencia,' which means salsa with 'awareness' or 'conscience,' and 'Mi Tumbao Social,' or 'My Social Drumbeat.' The band has also used YouTube, Facebook, MySpace and other social media extensively to promote its music. In addition the BBC has released a DVD of a performance in January at the Barbican in London, though that is still unavailable in the United States. 'One thing I like about this band is that you don't get the feeling they are in this to get rich or be the next big thing,' said the composer, producer and musicologist Ned Sublette. 'This is a fiesta popular. They seem to be about roots, about continuing the tradition and moving it forward, unlike the salsa lite that's on the radio. And I also like the fact they are a real working band with consistent membership, which is hard to do in New York.' Commercially, however, the path the band has chosen is an uphill one. La Excelencia's insistence on 'doing what we want the way we want it and not worrying about anything else,' as Silva puts it, has won the band a dedicated following but not huge acclaim or success. Neither CD has yet sold more than 15,000 copies, though they have flourished as digital downloads. 'As far as Latin radio in the U.S. is concerned, the market for what they do is practically nonexistent, extinct,' said Sergio George, the producer and arranger best known for his work with Marc Anthony and other salsa romantica artists. 'This is a band that for sure can succeed in festivals in Europe, because over there a great community supports that kind of thing. But in the U.S. it's tough sledding.' La Excelencia tries to compensate for that with a dynamic live show, meant to draw young listeners whose attitude, as Silva describes it, is likely to be: 'Salsa? That's my dad's music. My grandfather listened to that stuff.' On 'Unidad,' for instance, Vazquez takes his drum out into the audience, and the rest of the band follows. The older, more established generation of salsa musicians and promoters appears to have an ambivalent attitude about the group. Rafael Ithier, leader of El Gran Combo of Puerto Rico, perhaps the genre's most popular and respected working band, has emerged as a patron, going so far as to call publicly late last year for salsa fans 'to support the boys in La Excelencia.' But New York club owners often complain about the band's insistence on wearing sneakers and street clothes onstage, instead of the fancy shoes and suits that are almost obligatory. And members of some other local bands have been known to grumble that La Excelencia sounds 'too Colombian,' by which they mean that the group plays too fast for their taste and is too brassy, in the style of Grupo Niche. 'I really don't agree with that,' said Pablo Yglesias, author of 'The Rough Guide to Salsa' and other books. 'The truth is that La Excelencia is a mixture of the retro and the contemporary. I think they just see themselves as playing great music and not caring about fashion, so they are fresh that way.' 