With the final note of Haydn’s “Lord Nelson,” Sunday at the Barre Opera House, one audience member blurted out “Wow!” And he was right. The Randolph Singers and the Vermont Philharmonic had performed superbly. Although both groups are “community” ensembles made up largely of amateurs, their performance was truly exciting — even to this jaded old reviewer. Over the years, the words "community" and "amateur" have gotten an undeserved bad rap. And that’s because there are two kinds of community/amateur performance. One is for fun, for folks to enjoy a relaxing get-together to practice and perform for friends and neighbors with decidedly amateur results. And there’s absolutely nothing wrong with this. Sunday’s performance was anything but that. Both groups are filled with serious musicians who make a living doing something else. Members prepare in advance and rehearse religiously. And the rehearsals, under professional conductors, aren’t always fun. But they love it. They want to be the very best they can be and are willing — even want — to tolerate the intense scrutiny and guidance. Both organizations have had a lot of practice. The Randolph Singers are beginning their 50th year, and the Vermont Philharmonic begins its 60th season in the fall, making it the oldest community orchestra in the state. Franz Joseph Haydn’s Mass No. 11 in D minor, called “Lord Nelson” celebrating his successful battle with Napoleon, is one of Haydn’s greatest works, and of the Classical repertoire. Haydn had access to topnotch soloists, chorus and orchestra, so this isn’t dumbed down for amateur forces. The Randolph Singers, directed by Dick and Marjorie Drysdale (also a brilliant soprano), performed expressively with a rich, blended sound and very good diction. (Yes, you could understand the words.) More than that they responded to conductor Lou Kosma’s directions with subtlety and nuance. And they sounded great. And the Philharmonic, led by Kosma now for the 19th year, never played better. The accompaniment in the Mass is predominantly strings, and the Philharmonic’s had found a newfound discipline (thanks in part to professional concertmaster Letitia Quante). You could see it in their uniform bowings, and hear the pitch-accurate and well-articulated sound. Most importantly, they followed Kosma’s slightest direction, collaborated sensitively with the singers and delivered the joy. Wisely, the soloists were opera-trained professionals. Young soprano Stephanie Leotsakos, who had most of the solo work, sang with brilliance and expressiveness, emanating from the orchestra beautifully. Soprano Elizabeth Perryman delivered the alto arias with a rich warmth. Vermont tenor Adam Hall sang with brilliant lyricism, and baritone Thomas Read achieved a beautifully dark gravitas. But individuality wasn’t key in this work, as there weren’t separate solo arias and choruses; rather, the soloists emanated from and in between choral sections seamlessly. Kosma’s masterful direction (he was, after all, a bass player at the Metropolitan Opera for some 30 years) of his inspired musicians forces the verdict: Wow! Another professional on the program was Frank Foerster, principal violist of the New Jersey Symphony. He was the able soloist in his own charming Scandinavian Suite for solo viola and strings. After a prelude, each movement was an attractive and often virtuosic treatment of a folk melody from five different countries. Against a backdrop of sensitive Philharmonic strings under Kosma, Foerster played this compelling work with warm lyricism and easy virtuosity. The program opened with Johannes Brahms’ Variation on a Theme by Haydn, Opus 56, involving the entire 48-piece orchestra. Although a bit reserved, Sunday’s performance reflected the discipline and spirit of the Haydn. It was a rich and satisfying performance. The community/amateur movement in Vermont in huge. You owe it to yourself to check it out. Jim Lowe is music critic and arts editor of The Times Argus and Rutland Herald, and can be reached at email@example.com or firstname.lastname@example.org.