Fantastic music visualizer, it can stand alone as an app taking Line-
In or Internal CD, and it has plug-in varieties for many music player
apps: iTunes, SoundJam, Audion, MACAST, MacAMP, Winamp, Sonique.
WhiteCap began its career as freeware. Whitecaps are turbulent crests
of waves on water. Rather than all abstract rendering such as G-Force,
WhiteCap has themed programs called Configs each with its own built-in
color schemes. Some configs are highbrow artistic (like "Summer Night
Beach") so you'll need to press the 'L' key to see the config title in
order to "get" some of the humor. Impressive is how the configs morph
from one to the next.

1st DL: is v4.0 (February 21 2001) containing only the standalone
version, and a G4-enhanced variety of itself, plus many "Extra"
Configs (program text files). There won't be a v4.0 plug-in for iTunes
because this predates the release of Apple iTunes.

2nd DL: 4.1.2 Standalone

3rd DL: Full installer for version 4.2.1

4th DL: is v4.5.8 (January 2004) contents extracted from archive as it
appears on Macworld cover CD 21.04 Apr 2004, this was intended for OS
X only and I couldn't make the iTunes plug-in work in OS9. But the
standalone app is Carbon so it works in both OS X and 9. WhiteCap
v4.5.8 performs significantly smoother and faster than v4.0 , tested
on MDD2003 with 1344x840 fullscreen resolution on a 1920x1200 display.
Version History implies nothing less than v4.5.8 is worth much.

After launching WhiteCap once, Quit it, then edit the "WhiteCap Prefs"
file most recently modified in your "System Folder/Preferences/".
Increase its values of 'MaxX' and 'MaxY' as needed (v4.0 only), and
change "FS_X" and "FS_Y" values to your desired fullscreen resolution.

Various WhiteCap v3.n for SoundJam, Audion, MACAST, and MacAMP are
found in their respective music player downloads. SoundJam's WhiteCap
v3.2 contains its source code.

WhiteCap 4.x does mirror the rendering engine and complexity of
another visualizer named "G-Force" 2.x, so WhiteCap 4.0 is a lot like
G-Force 2.0, WhiteCap 4.5 is like G-Force 2.5, and WhiteCap 4.7 is
like G-Force 2.7 (they're both for OS X only).

Recommended 4U by SkyCapt: install v4.5.8 , erase 2 bad Configs
"Factory" and "Storm Beat" , copy in 2 nice Configs found in v4.0
"DTSD - Stormy Rainbow" and "NCC-1701" , copy in 9 nice Configs found
in v4.0 Extras : Ahhh The Sunsets, Bubble, Color Tube, Crystal Voyer,
Firecracker, Fireworks, Out of Mind, Sky II, Wicca. There are 2
Configs that need their Creator Code repaired to 'ttxt' : "O
Canada.txt" & "Tejas!.txt" - the remaining extra Configs look
unfinished or undesirable, "Factory" is a broken Config mimicing
what's seen when v4.5.8 launches and is too similar to "Title Track" ,
"Storm Beat" looks broken and disturbs continuity.

*Please locate a middle version which can be plugged into iTunes v2 on
OS9. Macworld magazine had a fondness for WhiteCap and G-Force,
perhaps their set of CDs has it.

See also: [G-Force for Classic][1], [WhiteCap for OS X][2]

Compatibility
Architecture: PPC

The author recommends a G3 processor or better.

  [1]: http://macintoshgarden.org/apps/g-force-20
  [2]: http://macintoshgarden.org/apps/whitecap