I've used eRampage before but had uninstalled it. I just reinstalled (v0.96) for another playthrough and now it crashes on startup, apparently when trying to initialize the music playback device. Last few lines of the log are:

Initializing music...
Loading OpenAL32.DLL
OpenAL Information:
Version: OpenAL version 1.1
Vendor: Creative Labs Inc.
Renderer: SB Audigy 2 ZS Audio [DF00]
Initializing sound...
Initializing MultiVoc...
- 16 voices, 1280 byte mixing buffers
Initializing DirectSound...
- Primary buffer format: 2 ch, 22050Hz, 8 bits
- Creating secondary buffer
S_PlayMusic(): error: can't open '' for playback!

That last line is particularly odd: can't open <blank> for playback?

Anybody have a clue what's wrong?

eRampage is outdated. If I were you, I would use either RedNukem, BuildGDX, or RAZE. If you do not want Java installed then use RedNukem. RedNukem is a fork of eDuke32 that has support for Duke Nukem 3D Atomic Edition, Redneck Rampage (RR), RR Rides Again and Duke Nukem 64 should you have a Duke 64 rom. I have never used eRampage so I have no idea what is wrong.

BuildGDX requires Java but is a good port, especially if you want all your Build Engine games from one launcher. It supports Duke 3D Atomic Edition, Duke 3D World Tour, Redneck Rampage (alongside both expansions), Shadow Warrior (and its expansions), Powerslave, and more.

RAZE is made by the people who made GZDoom so the interface is similar to the doom engine source port. It has its own fork of RedNukem. Like BuildGDX it is a great launcher for the Build Engine games and supports a wide variety of them. It mainly supports the Build Engine games that have had ports that had to do with eDuke32. So games like Duke 3D. Also Redneck Rampage because a fork of RedNukem is used (and as I previously stated, RedNukem is a fork of eDuke32).

eRampage is no longer supported to my knowledge so its better to use one of the modern source ports. Thats just my two cents though. I hope this helps.