Are you sure you checked the specific problematic songs all way through on your computer?

When burning to CD, it's best to (a) choose a good quality CD, not an el cheapo made in china or taiwan or somewhere. (b) Burn the CD at the minimum speed your burner & the disk allows it to. Rather than buy & choose a 45 speed disk, get a slower type such as 20 speed & burn at 4 or 8 speed. I find much more reliable results when doing so. High speed disks are more-so intended for data backup, not multimedia. Burning audio & video disks are the slowest rate possible has always been best choice for many years.

Your burner software 'might' be at fault. If your song files do play ok on the computer & you have double-confirmed this, then convert them all to WAV file format, then burn to CD. This will make it much easier for the burner software to process them during the burning process.

Oh I forgot to mention, some CD players do not like the high speed disks. Especially if the songs were burnt at high speeds. Another reason to choose the slower speed disks. Play the disk you used in your computer, see if it has that fading out effect. If no, then you know why. If yes, then looks like either quality of disk or burner software issue.