In Metal Gear Solid Delta: Snake Eater, the iconic Snake Eater song was re-recorded. In the video below, you can compare the new version to the original from Metal Gear Solid 3: Snake Eater.
Both songs are layered on top of each other at the start. You can then hear the songs separately. The two versions are both sung by Cynthia Harrell.
You can find the video, with time stamps, below:
0:00 Both Versions Combine with Opening Credits Comparison
2:51 Metal Gear Solid Delta Song and Opening Credits
5:48 Metal Gear Solid 3 Song and Opening Credits