You can sometimes find legal live recordings or promotional interviews that are free to download.
"Locked Out of Heaven," "When I Was Your Man," and "Treasure."
Includes "Lossless" and "Hi-Res Lossless" at no extra cost to subscribers. Internet Archive:
If you're interested in exploring Bruno Mars' discography, I recommend checking out his official music releases on streaming platforms or purchasing his albums from authorized music retailers.