It happened at the Batha Museum in the city's oldest quarter near the souq at Bab Boujloud, where the festival's intimate afternoon concerts are held in the museum's beautiful back garden. Somehow nearly a week's worth of performances had transpired without being interrupted by a muezzin chant; when the inevitable occurred, however, it wasn't so much a disturbance as a clarification. The audience let out a collective chuckle as the second strain of the late afternoon adhan ascended, easily drowning out the baroque devotional music being performed by Elyma, a Swiss chamber music ensemble specialising in Monteverdi. The musicians seemed to relish the opportunity to observe a moment of silence, resuming play once the muezzin had finished. The irony's underlying reminders - about the intersection of art and life, the efficacy of spiritual pilgrimages, perhaps even the juxtaposition of the ancient and the merely old - were indeed powerful. No one would deny that an adhan is as musical as any of the dozens of international acts (gospel singers and whirling dervishes, Sufis and cantors) presented at the festival each year, but a call to prayer is quite obviously not entertainment - something the festival organisers are keenly aware of as they seek a delicate balance between the aesthetics of foreign visitors and locals. Many Fez inhabitants pride themselves on remaining connected to a history that stretches back to the ninth century, even in the cafe-lined nouvelle section of the city, where motor scooters and red "petit taxis" vie with djellaba-clad pedestrians on cellphones. I overheard a number of journalists visiting town from other Moroccan cities grouse about conservatism in Fez, which seemed both accurate and a bit unfair in the context of the festival. It's true that locals don't seem much interested in Fez becoming a cosmopolitan playground for the jet set like Marrakech or Casablanca, but luckily, on my second visit to the Sacred Music Festival - which this year ran from May 29 to June 7 - I found that Fez isn't the type of city to allow its soul to be tarnished, even though in its 15 years of existence the festival has become a magnet for an international mix of music pilgrims and celebrities. When the Lebanese oud virtuoso Marcel Khalifé kicked things off this year at a red-carpet event at the Bab Al Makina, a breathtaking, walled outdoor amphitheatre that hosts the biggest-ticket events each evening, the place was abuzz with security, paparazzi and various dignitaries. As is customary, Morocco's Princess Laila Salma was in the house and the famed French-Moroccan actor Said Taghmaoui could also be spotted down in the front row. The Bab Makina, like the Batha Museum and several other venues utilised by the festival, is in what locals call Fez Jdid, the 12th-century imperial part of the city, enhancing the feeling that you've stepped into another world and another time. Back in 2007, the Irish rock band U2 arrived in Fez and not only attended the entire festival, but returned months later to take over the gorgeous open-air Riad al Yacout in the medina and record their current album, replete with the evocative single Fez - Being Born over a period of 17 days. It's quite possible that the attention generated by the festival is a key reason that portions of Fez beyond the walls of the old city now seem ripe for development, but there's not much chance of that altering its mission. Originally born out of a symposium for tolerance following the first Gulf War of the early 1990s, the event still adheres to the principle that any culture's sacred roots reveal its moral fibre or fundament and that it's possible to place each side by side and sometimes engage them in dialogue. It's a vision of one-worldism, certainly, but it also provides space for non-believers like myself to participate in the festivities. As an American, for me one of the oddest sensations of the event came the night that the New Orleans-based gospel singer Paulette Wright (subbing for the ailing Marva Wright - no relation - who had suffered a stroke weeks earlier) brought the house down at the Bab Makina. The sight of so many people in this city of 700 mosques on their feet, ecstatically clapping and singing "glory hallelujah!" along with Wright was unique indeed, but it gained added resonance less than an hour later when I visited one of the late-night "after-hours" performances held in the garden at Dar Tazi, a former municipal palace. For the entire week Dar Tazi was the province of Sufi ensembles, a revolving line-up of Muslim brotherhoods (and in the case of Deba des Femmes de Mayotte, sisterhoods) who chant their way to spiritual fulfilment. No doubt there were many people who identified as Christians helping out the fabulous Abdellah Yacoubbe Ensemble with its trancelike entreaties of "Wallah!" On the other hand there are offerings, like Khalifé's tribute to the renowned late Palestinian poet Mahmoud Darwish, that are indicative of the way the Sacred Music Festival's vision has widened since the early days. Not satisfied with merely gathering the music of religious traditions from around the globe, the artistic director, Gerard Kurdjian, a Nice-based French-Armenian who books the flagship events, has been steadily adding concerts by pop-based stars who traffic in socially conscious themes (the jazz singer Abbey Lincoln played in 2000, while the 2005 roster included the Senegalese superstar singer Youssou N'Dour). Two of the brightest lights of this year's line-up, the Algerian singer-songwriter Souad Massi and the Malian kora player Toumani Diabate's Symmetric Orchestra (the latter a brilliantly calibrated festival closer in lieu of the Celtic singer Loreena McKennitt, who cancelled citing personal reasons), have songs about not losing sight of traditions, spiritual and otherwise. "[Many] themes go hand in hand with the function of sacred music," Kurdjian told me. "Where religious musics are often related to rituals, I think sacred music can take into account the way art impacts ordinary life beyond the ritual moments." Diabate's band, in particular, put this to the test by playing a set of rousing griot music before engaging in a marvellous ritualistic finale with several Sufi troupes who had marched in to meet them from the rear of the Bab Makina. It's probably worth noting that several of the concerts that didn't quite gel this year erred on the side of ambition. French violinist Didier Lockwood ended up salvaging his jazz/classical/Arabic music commission by taking crowd-pleasing sprints with his instrument through the aisles of the Bab Makina, while Syrian vocalist Abed Azrie's sprawling oratorio, The Gospel According to John, saddled the finest student choir and orchestra I have ever heard with passages that showcased extraordinary talent but lacked cohesion. A similar fate befell Iranian percussionist/composer Keyvan Chemirani's multiculti work Melos: Chants of the Mediterranean, even though it's hard to imagine anyone leaving the show without taking note of the Spanish flamenco singer Esperanza Fernandez, whose full-throated interludes illustrated what the poet Federico Garcia Lorca meant when he wrote that the term duende was elusive but worth its weight in melancholy. Perhaps the most exciting development in recent years has been the rise of the satellite Festival in the City, a nightly selection of free public concerts. They are a sign that the Sacred Music Festival's organisers are truly interested in engaging the next generation of Fez locals. The idea for the free events was a direct response to the early criticism that the Sacred Music Festival aesthetic, as well as its prices, were prohibitive to everyone except tourists and Morocco's francophone elite. No small wonder that the City concerts yielded quite a few discoveries for a curious American like myself by bringing a mix of topical, raucously impressive Arabic rock (Haoussa), hip hop (H-Kayne, Mazagan) and back-to-the-future traditional performers (Nabyla Maan) to the kind of young, enthusiastic audiences I'm used to seeing in New York's Central Park. It was especially instructive watching Souad Massi, in her North African debut since settling in Paris at the turn of the millennium, put on startlingly different shows two nights running. Her performance at the Bab Al Makina was a buttoned-down chamber music affair that showcased her one-of-a-kind voice, while the next evening she added an electric bassist and a drummer and rocked the crowd at the medina gateway space Bab Boujloud. Mosh pits broke out as the crowd joined Massi in singalongs, their excitement a perfect match for her own. <b>For more about the Sacred Music Festival visit www.fesfestival.com</b>