The composer who writes and orchestrates original film music — the author of the score, not a library editor. Hans Zimmer, John Williams, Trent Reznor as reference.
You're sitting in the editing suite, the first rough cut is playing – and suddenly you realize: without the right music, nothing works. The composer is the one who creates that emotional space that you, as the cinematographer or editor, have only prepared visually. They don't work with archive material or production music libraries. They write originally for your film, according to your timings, your edits, your narrative logic.
You don't notice anything of this on set at first – the composer comes into play later, usually after Picture Lock. But their work begins with intensive discussions: the director explains the emotional framework, you and the sound designer have already determined how ambient pressure and silence function. The composer has to decide where music can breathe and where it actively guides you as a viewer. Some scenes need leitmotifs – recurring musical phrases that convey characters or conflicts. Others need pure atmosphere, barely recognizable as "music".
The practical reality: The composer writes on Digital Audio Workstations – notation software like Sibelius or Finale, then orchestration and arrangement. They work with tempo maps, hit points in the edit, create sketches that the director approves. Then comes the recording – usually with a real orchestra, session musicians in the studio, or they synthesize everything digitally. This is where it gets technical: timecode, synchronization, click tracks for the musicians. An error of three frames and the music is no longer in sync.
Your role as a practitioner is important: the composer needs to understand your edits, your rhythm. If you've edited a scene with a specific tempo, the music must respect that – or deliberately work against it. Some composers deliver multiple versions: music with string entries, without, with brass accents. In the final mix, the balance is then weighed: music level, dynamics, interaction with dialogue and sound design. The composer is often present during dubbing – their music is not a finished constant, but is integrated live into the context.