At a time when Roman Catholics and Episcopalians seem to be growing ever-further apart, gestures of unity are always refreshing. That’s why Summer Music at the Cathedrals, a musical partnership between Our Town’s Catholic and the Episcopal cathedrals downtown, is a welcome addition to the upwelling of local performing arts during the last decade. This annual mini-festival of instrumental, vocal and choral music takes place at 2 p.m. each Sunday in August — two at the Cathedral of the Immaculate Conception and three at Grace and Holy Trinity Cathedral.

“It’s pretty much unique between these particular churches,” said John Schaefer, canon musician and organist at Grace and Holy Trinity. “We’ve been doing it a long time and we’ve made a lot of good music over the years.” In 1974, the two cathedrals — which are located a block apart just west of the Convention Center — entered into a “covenant of sharing.” Downtown churches often have common concerns, John said, including the need to encourage spirituality in an often-challenging urban setting, and a commitment to social action. The Summer Music partnership was an outgrowth of that covenant, and it continues to be a source of communication between the two faith groups.

This year the Summer Music series has scored perhaps the biggest coup in its decade-long partnership: the engagement of internationally renowned organist Hector Olivera, for a recital on Immaculate Conception’s 50-rank Fratelli Ruffatti organ. The Argentina-born organist is known for brilliant technique, deep musicianship and energetic interaction with audiences. His appearance is thanks to the efforts of Mario Pearson, director of music and liturgy at Immaculate Conception, who has worked together with Schaefer on the series as had his predecessor, John Winkels.

“Hector Olivera is in a class by himself,” wrote a critic in the Atlanta Journal-Constitution. Born in Buenos Aires, Hector began study at the Buenos Aires Conservatory at the age of 6. He later moved to New York to study at the Juilliard School, and in the ensuing years he quickly became one of the most sought-after concert organists in the world. His program here will include Bach’s mighty Passacaglia and Fugue in C minor, Frank’s Prelude, Fugue and Variation, Liszt’s Weinen, Klagen, Sorgen, Zagen! and other works. He will also improvise on a theme submitted to him on the spot. “The performance by Mr. Olivera is perhaps the most daring thing that we’ve done,” John said. (It seems fitting, seeing as the American Guild of Organists named 2008-2009 “The International Year of the Organ.”)

Also in the spirit of religious unity is an organ recital by Anne Marie Rigler, associate professor of music and college organist at William Jewell College. Her program, “God of Many Names,” is an exploration of organ compositions representing several of the world’s faith traditions. The program draws its title from a hymn of the same title by British hymn poet Brian Wren: “God of many names, gathered into one … is the God whom we proclaim. … Great God of many names: Jehovah, Allah, Lord, Christ, Brahman, Spirit, Adonai; we worship you.” John said Anne Marie is one of a triumvirate of marvelous women organists in Kansas City — the others being Jan van Otterloo and Jan Kraybill — who give the local male organists a run for their money. She will perform on Grace and Holy Trinity’s 67-rank Gabriel Kney organ, which was installed in 1981 and renovated in 2004 by Leslie Smith and Quimby Pipe Organs.

The series continues with a recital by soprano Amy Waldron, a member of Octarium (and former Kansas City Chorale member) and a key figure in the local vocal and choral scene. (Earlier this summer, Amy and others put together the debut performances of the Simon Carrington Singers, to honor and showcase her former University of Kansas choral mentor.) Her vocal recital is followed by an annual concert of the Summer Singers of Kansas City, under William Baker’s direction, in a program that includes Mozart “Great” Mass in C minor. Finally, John himself will be joined by the Missouri Brass quintet — members of the U.M.K.C. Conservatory of Music and Dance faculty — for a concert including music of Bach, Richard Strauss, Dukas, Hovhaness, Mendelssohn and the American composer Eric Ewazen.

Summer Music at the Cathedrals

All programs are at 2 p.m. and are free (with a $10 donation requested) except where noted. For more information call 816-474-8260. CIC: Cathedral of the Immaculate Conception. GHTC: Grace and Holy Trinity Cathedral.

August 2nd: Hector Olivera, organ, CIC ($20, call 816-842-0216, ext. 119)

August 9th: Anne Marie Rigler, organ, GHTC

August 16th: Amy Waldron, soprano, GHTC

August 23rd (repeated at 7:30 p.m. August 24th): The Summer Singers of Kansas City, conducted by William Baker, CHTC ($20, $10 for seniors and students, 12 and under free; call 816-235-6222 or go to www.festivalsingers.org)

August 30th: Missouri Brass Quintet with John Schaefer, organ, CIC

To reach Paul Horsley, performing arts editor, send email to phorsley@sbcglobal.net