The problem, in my mind, is that every single one of these articles misses the point completely. Even if you implemented a call centre system that detected and automatically played someone’s all-time favourite music while they waited, a facility which is possibly not that far off, most music when played down the phone just sounds terrible. Butchering a song that someone actually likes is unlikely to improve the waiting experience.
Set the right tone for the call by introducing your business in a welcoming manner. The message can be played either by itself or as an intro to IVR prompts.

It seems pretty self-explanatory: on-hold messages are messages that play “on hold” over your telephone system. These professionally produced recordings are also an integral part of your company’s marketing strategy. By providing timely, relevant information about your business, an on-hold messaging program reinforces current marketing campaigns and builds brand recognition. This in turn increases call retention by improving the caller experience. To top it all off, it also increases sales by targeting key demographics.
So modern technology, even with the most advanced VoIP business phone systems, has not improved the plight of the on hold song. If you are interested in learning more, check out Tom Scott's explanation at the Milton Keynes Museum, in their Connected Earth gallery.