The director of Head-On investigates the rich musical culture of his homeland.

The soundtrack and score of the critically acclaimed, adrenaline fueled doomed romance Head-On was a fusion of punk, European electronica, hip-hop, British new wave and traditional Turkish laments, so it’s no great surprise that the Turkish-German director Fatih Akin’s new movie is a documentary about the vibrant and diverse music community in Istanbul. It’s the city where Head-On music composer Alexander Hacke, better known as a member of the avant-garde band Einstuezende Neubauten, recorded a few songs for Head-On — and became fascinated by the diverse musical styles and how they are representative of a city bursting at the seams with vitality, originality and the delight of “East meets West,” creating something new. In other words, Crossing the Bridge is about that bridge between cultures, which is to say, it’s about Istanbul.

The documentary’s structure is decidedly shambolic, with a mostly handheld camera following fast on the heels of the long-haired, bearded, intense-looking Hacke as he ventures from one district to another, hauling along a portable recording studio on his computer and a case full of microphones. Their journey begins with a neo-psychedelic band called Baba Zula indulging in a jam session aboard a boat — and since their bass player dropped out at the last minute, Hacke is more than happy to jump in. A half-dozen bands later, ranging from intellectual experimentalists in a pastel-colored basement to Turkish rappers who frown on the idea of “gangsta rap” and imbue their fast lyrics with historical and philosophical heft, Crossing the Bridge detours into the poverty row world of gypsy performers in a Bohemian beer garden and folklore street performers and break-dancers who inhabit the public square of Istanbul, proposing musical development as an alternative to drug culture.

This fast-moving trip into the musical heart of a city doesn’t take breaks to reorient the viewer, other than a few cursory insights from Hacke on where they are and an overview of the performers on hand. What’s more vital is the spirited enthusiasm and excitement of each encounter. A favorite is the charismatic Orhan Gencebay, a sometime Turkish movie star (clips from his action movies make for fine kitsch) and “the hero of cab drivers and the working man,” and the Kurdish female singer Anyur, now able to perform in Istanbul using her mother tongue. At one time this would be grounds for persecution, but given the sea change that happened with Turkey’s becoming a part of the European Union, she’s allowed to perform her ethnic ballads, which are purely beautiful as well as haunting in their unfiltered expression of sorrow.

One wishes the filmmaker would slow down, since the American saxophone player who fronts the band Orient Expressions says fascinating things about how the current White House administration incites a gap between Eastern and Western culture, as if making a chasm between order and chaos — the “clash of civilizations.” The sound bite registers offense and gives America’s present administration the finger, which is cathartic, but in the rush of information big ideas like this get swept up into the musical collage, and don’t register as much as they should. But taken as a whole, Crossing the Bridge offers a wondrous and useful primer on Istanbul’s music community. Imagine a 20-course meal where every dish offers new tastes and smells, one subtle and the other sweet, followed by something spicy and something refreshingly cold and cleansing. The food analogy seems apt, because it conveys the palpable substance of each band. Even though the documentary sprints through, each of these musicians makes a vivid and eye-popping impression.