The Lesbian & Gay Big Apple Corps (LGBAC), one of our community's treasures, which many know best as the marching band we've cheered on the last Sunday in June, during the past three decades of Pride Marches, also makes a more formal presence as the Lesbian & Gay Big Apple Corps Symphonic Band, and it is in this concert incarnation that the Corps will perform on April 24 at 8 p.m. at the Julia Richman Complex, 317 East 67th Street, at Second Avenue, in a program billed as "Symphonic Power!" and promising, in its subtitle, "a Dynamic Evening of Music." LGBAC's spring outing features, as the band's publicity puts it, "four grand works celebrating the beauty and majesty of the symphonic form" and Brooklyn native Brian P. Worsdale, the Symphonic Band's artistic director since 2005, will conduct.

Pianist, composer and educator James Adler ("Memento Mori: An AIDS Requiem," Prelude and Toccata, "Two Dances in One-Calypso cum Cakewalk"), a frequent guest artist with the Corps, will be the soloist in Sergey Vasilyevich Rachmaninoff's Concerto for Piano and Orchestra Number 2 in C minor, Opus 18, in a band transcription by Adler's longtime life partner flautist Scott Oaks, which is sure to be a highlight of the evening. Rachmaninoff wrote the three-movement concerto at the beginning of the 20th century after three years of 'composer's block'-which he traced to the disastrous premiere of his First Symphony, reportedly poorly conducted by composer Alexander Kostantinovich Glazunov-and four months of daily hypnosis and autosuggestion therapy with Dr. Nikolai Dahl, to whom Rachmaninoff dedicated the concerto. A 1940s hit popular song, "Full Moon and Empty Arms," notably recorded by Frank Sinatra, was derived from the sweeping second theme of the third and last movement, the allegro scherzando. James Adler teaches at St. Peter's College in New Jersey and, in summers, at the French Woods Festival of the Performing Arts in the Catskills.

The Corps also investigates Symphony Number 1 for symphonic band, "The Divine Comedy," by prolific contemporary American composer and arranger Robert W. Smith, who teaches at Troy University, his alma mater, in Alabama. Inspired by Dante Alighieri's 14th century "La Divina Commedia," the symphony's movements are entitled "The Inferno," "Purgatorio," "The Ascension," and "Paradiso."

Peter Ilyich Tchaikovsky's Overture Solennelle "1812," Opus 49, more familiarly known as the "1812 Overture," including Russian hymns and folk melodies, and French national anthem "La Marseillaise," and calling for cannons and church bells, is another perennial favorite LGBAC will offer. The "American Overture" for band, by Pennsylvanian composer, arranger, church organist and choirmaster Dr. Joseph Wilcox Jenkins, will complete the program.

Tickets are priced at $20 at the door or $15 for students and seniors or in advance at www.lgbac.org. For further information and reservations, telephone 212/591-2886 or go to the Corps' web site.