On hold music is the worst, and kind of perverse. It is designed, I assume, to assure the caller that they are still on the line, and that they should just continue to wait. However, for the caller it has an undesirable consequence: the shorter the call, the less assurance you need, but the longer the call, the more you want the music to get out of the way.
When I am put on hold, I put my phone on speaker so that I can continue to work at my computer while I wait. As time goes on, the music grates on the back of my mind, threatening to distract me, though I can tune it out to some degree.
However, some call systems have the most obscene habit of interrupting the music at regular intervals so that a voice recording can assure me that I am still on hold and they will connect me as soon as possible. This means that I can’t turn the music down to a less invasive volume level, because every now and then the music stops, and I can’t be sure that it was to play the recording or because I now am no longer on hold. If I turn the sound down, I regularly have to turn it up when I hear the music disappear, just to check if I’ve actually been connected, which is most inconvenient. So instead, I am forced to leave the volume for the music up, and shift my attention from my work back to my phone every few minutes when I hear it stop. It actively works against my ability to concentrate on something else while I wait.
Ideally, on hold services would provide those waiting on hold with an option for some unobtrusive regular beep or noise, instead of music, with no interruptions other than when I am finally connected. Perhaps some on hold services offer this feature, but I’ve not heard of a way to activate them if they do.