Steven Moeckel compares it to training for a 10K, even though he and pianist Paula Fan will spend most of the day Sunday sitting or standing.
For weeks, they've been practicing the music they will perform during their 12-hour marathon concert at the Tucson Scottish Rite Temple. He's been rehearsing with the student musicians who will join them for parts of the day, and his colleagues from the Tucson Symphony Orchestra and Phoenix Symphony.
Moeckel realizes a Herculean task awaits him - 12 hours broken into two-hour segments, each with a 20-minute intermission.
Think of it as doing six two-hour concerts all in a row.
"It will be doable; it's just a matter of learning how to manage your energy level," an optimistic Moeckel said last month. "People are thrilled, and they think I'm crazy. But I get that a lot."
"This is part of us both being enthusiasts - or crazy," added Fan.
The concert is a way for the pair to celebrate the 10th anniversary of their friendship and musical collaborations. Proceeds from the concert will benefit Open Inn, an organization that helps at-risk and homeless teens and their families.
Fan and Moeckel will survey their years of collaboration, drawing from their three CDs, which include works by Brahms, Tchaikovsky, Sibelius, Camille Saint-Saëns, de Falla, Elgar and Strauss.
"We've done so much repertoire it's going to be fun revisiting old friends, so to speak," said Moeckel, 35, the former Tucson Symphony Orchestra concertmaster who is now concertmaster with Phoenix Symphony.
The pair have invited musicians from both orchestras as well as student musicians from Tucson to participate in the concert. Moeckel and Fan will perform in each segment.
"We're excited about it, but there's also the prospect of the unknown," said Fan, 60, who said she has never performed 12 hours straight before."But because I'm doing it with my partner in crime that I've known for so long, we're very excited."
If you go
• What: "Playing for the Future," a marathon concert to benefit Open Inn.
• Featuring: Steven Moeckel and Paula Fan, with musicians from the Tucson Symphony Orchestra, Phoenix Symphony and several high school orchestras.
• When: 10 a.m. to 10 p.m. Sunday.
• Where: Tucson Scottish Rite Cathedral, 160 S. Scott Ave.
• Tickets: $50 for an all-day pass, $10 per two-hour segment by calling 301-7201.
10 a.m. Recital segment - Brahms' Scherzo for violin and piano; Prokofiev's Sonata in D major; Beethoven's Sonata in A major Op. 12 No. 2; Sarasate's "Carmen" Fantasy.
Noon Youth segment - Warlock's "Capriole" Suite; Mozart's Violin Concerto No. 5 "Turkish"; Mozart's Piano concerto No. 21 "Elvira Madigan" with Canyon del Oro High School Symphonic Orchestra; Schubert's "Death and the Maiden" for String Orchestra; Bach's Concerto for Two Violins featuring Moeckel and soloist from the Rincon/University High School Chamber Strings; Vivaldi's Concerto for Two Violins with Dennis Bouret and David Rife; Mendelssohn's Concerto for Violin, Piano and String Orchestra with Tucson Junior Strings; choral works featuring Tucson High Troubadours.
• 2 p.m. Concerto segment - Brahms' Violin Concerto in D major; Tchaikovsky's Violin Concerto in D major.
• 4 p.m. Chamber segment - Dvorak's Terzetto for Two Violins and Viola, featuring Maggie Martinic-Jercic and Matt Gordon; Halverson's Passacaglia for Violin and Viola, with Gordon; Sarasate's Navarra for Two Violins, featuring Martinic-Jercic; Schumann's Piano Quintet with Martinic-Jercic, Gordon and Mary Dibartolo; Beethoven's Duo for Violin and Contrabass with Jim Karrer; Maurer's Concertante for Four Violins, with Martinic, Carla Ecker and Ellen Chamberlain; Mendelssohn's Octet in E-flat Major, featuring Martinic, Ecker, Chamberlain, Gordon, Ilona Vukovic-Gay, Anne Gratz and Rob Chamberlain.
• 6 p.m. Wish segment - For a $40 or $60 donation, Fan and Moeckel will perform works off of one of their three CDs.
• 8 p.m. Pops segment - Jazz, pop, rock, country and mariachi works.
• Silent auction: From 3 to 7 p.m., you can bid on items including original Japanese artwork and a signed Salvador Dali print.