Most relaxation music is set at roughly 60 beats per minute (BPM), which encourages the brain to produce alpha waves—the frequency associated with a relaxed, conscious mind.

Science suggests that the body often needs at least 15 to 20 minutes just to enter a state of "rest and digest". A 50-minute track provides a sustained environment that allows for:

For those using music for insomnia, a 50-minute song is long enough to cover the initial sleep onset phase, ensuring you aren't jolted awake by a sudden silence or an ad. Top Genres for 50-Minute Relaxation

The Power of 50-Minute Mind Relaxing Songs: Your Guide to Deep Calm

Not all "chill" music is created equal. Depending on your needs, certain genres perform better than others: How Music Affects Mental Health - WebMD