Where it works
Works for memorials, emotional story moments and reflective endings. Use it briefly; long sad beds can drag a video down.
Building it in practice
The most convincing sad tracks leave space. One instrument carrying a slow melody, with long pauses and soft reverb, usually lands harder than a full orchestra. Ask for the arrangement to stay sparse for at least the first half, and decide whether you want hopeless or bittersweet: adding a single major chord near the end turns grief into reflection, which suits memorial videos and endings better.
Prompts to try
Sad solo piano piece, slow and sparse, falling melody, soft pedal, intimate
Emotional cello and string ensemble, minor key, builds gently then fades
Melancholic lo-fi with a slow detuned piano and rain