Diablo 1 and 2 have shared the same OST for Tristram, the music being composed by Matt Uelmen, an American artist.
All the Diablo 3 music was composed by Russell Brower, including the new Tristram version.
Comparing both songs, the first one definitely sounds more old school, the song from Tristram in Diablo 2 being the icon of the game along the menu symbols.
“Tristram village’, the action in Diablo 1 has its starting point as Tristram village, from where the player can go to different zones. The town was built by King Leoric.
Tristram in Diablo 2 is the place from where our character will rescue Cain (the character that appears in Diablo 3).
New Tristram in Diablo 3 is the first town where we arrive as we advance from the start, “Old Tristram” should actually be the town that was in Diablo 1 along the Cathedral, another icon for the Diablo series.
There is some background story about Tristram that can be found either on Wikipedia or different wiki Diablo websites.
Even on YouTube, there are some covers made by different singers, the old song is very interesting indeed and the one from Diablo 3 is what brings nostalgia for old school players even though the version is modified to today’s standards, sounding more friendly and more enjoyable.