There can be tunes that are good to make your 3-months-old baby sleep peacefully, or to motivate yourself when you are in the gym, or to help you focus on what you are doing.
I always try to seek for new songs, but as time passes by, it is always more difficult since there are not so many good songs realeased each year (or I have not time enough to keep me updated).
So, a couple of soft songs for helping your baby to sleep:
And some others to help you focus on what you are doing (maybe at work):
The last one has a wonderful video. It makes you love the actress, Maya Deren.