This mod is a remake of the OST and ambience tracks for the first game. The entire soundtrack and background ambience sound have been reimagined with their counterpart performed by the Royal Philarmonic Orchestra. A few tracks were replaced with their Tomb Raider Anniversary counterpart. You can manually choose using the list below which song you want to have or not in your game! Copy and paste the ones you want from the folder.

NEW: The original soundtrack was mainly replaced with their performance by the Royal Philarmonic Orchestra. Ambience sounds kept the original backing track but are now mixed with a more consistent and present ambience. SFX are untouched. The secret chimes have been updated.
I tried to keep the original vibe of the game with a very silent ambience.

I'd recommend using this mod if you've already played TR a lot and want to play the game with a brand new SOUND experience. The soundtrack has simply been "upscaled" in quality so it sounds crisp but the samples are the same as in the original 1996 game which I found to sound a bit too "old fashioned" in comparison with the very fresh and modern graphics. Some like the charm of it. I'm not a fan of it given how good the game looks, I'd have loved a better makeover of the soundtrack. To each their own!

Note: I couldn't upload a comparison video because Nvidia and OBS cannot record the game for some reason on my side and I have yet to find a solution for this. You might want to just play the first level with the mod. It will show you what to expect for the full game! If we ever find a way to change the SFX, I'll make a mod for that too. Those old gun shooting sfx aren't my cup of tea.

Here's the song list

("track file number" - "original game track" => "modern track")
 
2 - Tomb Raider Theme => Tomb Raider Theme (Orchestra)
3 - Tomb of Tihocan => Waterfall from Tomb Raider Anniversary (TRA)
4 - Shorter version of track 2 => Tomb Raider Theme (Orchestra), trimmed.
5 - The Caves (ambience) => Cave ambience music by LittleRobotSoundFactory (copyright free) mixed with the original ambience sound for fidelity reasons
6 - Jacqueline Natla (final boss theme) => Time to Run (Orchestra) full version
7 - St. Francis Folly => A Friend Since Gone (Orchestra) (Alternative name of St. Francis Folly track)
8 - Showdown (battle theme) => Raptor Theme from TRA (1:1 reproduction) 
9 - Peruvian Caves => Ghostly Presence by Two Steps from Hell (this one has a very mysterious vibe and I couldn't find anything else suitable. If you wish to keep the original song, do not copy and paste the file "9")
10 - The Plot Thickens => Longing for Home (Orchestra) (Alternative name of "The Plot Thickens")
11 - Anticipation => *unchanged*
12 - Danger => *unchanged*
13 - Secret => Secret Chimes from TRA (altered pitch)
14 - Revealed => *unchanged*
15 - Tomb of Qualopec => Tomb of Qualopec from TRA
16 - Gruesome Encounter (T-Rex theme) => T-Rex Theme (Orchestra), shortened
17 - The Lost Valley => Where the Depths Unfold (Orchestra) 
18 - Sanctuary of the Scion => Where the Depths Unfold (Orchestra) (this song is a compilation of The Lost Valley and Sanctuary of the Scion so I just trimmed the song into two different tracks)
19 - Authentic Tomb Raider => Tomb Raider Theme (Orchestra) trimmed (this track is actually the middle part of the Main Theme)
20 - Time to Run => Time to Run (Orchestra) shortened (Track 6 and 20 are almost the same song so I kept this characteristic)
21 - Epilogue => Longing for Home (Orchestra) trimmed (Track 10 and 21 are the same, 10 is the long version)
57 - The Cistern (ambience) => Tomb of Tihocan (ambience noise) from TRA
58 - Greece (ambience) => Desert ambience sound (copyright free) by Sound Diary
59 - The Great Pyramid (ambience) => Inside a Monster by TheAmbienceChannel (copyright free) mixed with the original ambience (sounds of heartbeat) for fidelity reasons


All rights to the original composers. If you do NOT want your music to be featured in this mod, please inform me as soon as you can!

Installation:

1 - Find the TRACKS folder of Tomb Raider 1 at C:\Programs\steamapps\common\Tomb Raider I-III Remastered\1\TRACKS
2 - Make a backup of the TRACKS folder (copy and paste it somewhere else so you can reinstall the original tracks if you want)
3 - Copy the content of the MODDED TRACKS folder you've downloaded.
4 - Paste it in that TRACKS folder you made a backup of (at C:\Programs\steamapps\common\Tomb Raider I-III Remastered\1\TRACKS)
5 - Your system will ask you if you wish to replace the files. Select "yes". Done!