Fatih Akin’s new documentary, “Crossing the Bridge: The Sound of Istanbul,” rethinks the boundaries of contemporary pop music.The film documents the contemporary music scene in Istanbul, and its incessant obsession with the East-meets-West influences of Turkish music would be wearisome if it weren’t so powerful. Listening to modern American rock music broken into ninths and spit back in a highly rhythmic foreign tongue provides a visceral rush almost akin to hearing rock music for the first time.

Early in the documentary, the Turkish neo-psychedelic band Baba Zula plans a recording session on board a boat in the Bosphorus strait as the sun sets over Istanbul. “We grew up listening to Zeki Muren and Pink Floyd, didn’t like either and now we’ve found the middle ground,” says one of the band members looking into the camera with a vast expanse of water behind him. Even if you don’t know who Zeki Muren is – the godfather of modern classical Turkish music – when the band’s delayed and reverbed ouds (a traditional lute-like instrument) echo across the city on both sides of the strait, the description makes perfect sense.

The film provides a formidable musical tour guide in Alexander Hacke. Mr. Hacke is the bass player for the seminal industrial German band Einsturzende Neubauten. At the beginning of the film, Mr. Hacke shows up in Istanbul with trunks full of recording equipment. He’s a well-known musician and producer, but more than that, he acts as a kindred spirit to all of the vastly different musicians he encounters, bringing something special out of each of them.

The breadth of styles and musical traditions the film covers is astonishing. There’s the aforementioned psychedelic Baba Zula; the rock Duman; the experimental Replikas; DJ collective Orient Expressions; rapper Ceza, whose machine gun delivery puts Eminem to shame; persecuted Kurdish singer Aynur; the “Elvis of Arabesque” Orhan Gencebay; and the shockingly soulful voice of Sezen Aksu, the Turkish Barbra Streisand and plastic surgery victim – to name a few.

Every performer in the film has much to offer. And this being Istanbul,the film is also a visual treat. Mr. Akin is clearly gifted – his passing shots of nightlife in the Beyoglu district of the city are such intriguing tableaux they could practically be a film unto themselves.

Further, Mr. Hacke utilizes the city itself in recording the performers – by interacting with street musicians or choosing the perfect recording venue. As if the Kurdish songs of Anyur weren’t heartrending enough, listening to her sing about the suffering of her people is only more affecting when the natural reverb of her voice bounces off the stone walls of a gorgeous 18th-century Turkish spa.

The political underpinnings of the documentary, however, feel underdeveloped. As late as 1990, Anyur wasn’t allowed to sing in public because of a government ban on certain kinds of music, due to secular Turkey’s misguided attempts to preserve national unity. The specter of Islamist radicalism in the Muslim world also hangs over the film. Istanbul is still a place where homosexuals walk the street and rock stars appear on camera holding beer bottles; undoubtedly such freedom enables the fertile music scene. Yet the emerging Muslim counterculture is repressive. One shot highlights a bit of street graffiti that reads “hip hop no muslim yes.”

To be fair, “Crossing the Bridge” is not a political film. It is, however, an aural delight and utterly convinces that the Turkish music scene is ready to explode in the West. Early in the film it’s noted that the lead singer of Duman went looking for success in Seattle at the height of the grunge mania, notably the last regional music scene that emerged onto the world stage fully formed.

If “Crossing the Bridge” ever makes it to art houses in Seattle, there are going to be a lot of unemployed musicians booking passage on the Orient Express, hoping to get to Istanbul before hype consumes the place.