These posts exist to provide guidance + information on SPECIFiC MODELS which provide SUPPORT FOR MAC OS 9 to those who wish to use an old powermac g4 for music purposes! If its not linked or pictured here, even if its very similiar!, theres a good chance that there are complications with compatibility, but these are the ones we RECCOMMEND for use with mac os 9 to those without experience! If you have experience or know of any other models that you can confirm compatibility with, from personal experience, feel free to post here + add to our information!! keep in mind any keyboard with midi can be connected via a midi interface to become a midi keyboard but these natively supported usb devices may provide extended functionality
http://www.soundonsound.com/sos/1994_articles/dec94/midicontrollers.htmlhttp://www.soundonsound.com/sos/1995_articles/jan95/midicontrollers2.html
Akai Mpd 16
drivers:
http://www.akaipro.com/product/mpd16#downloadsRoland ED PC-300http://www.roland.com/products/en/PC-300/
edirol pc-50
http://www.rolandus.com/products/details/745/downloads(it seems the edirol PCR Mseries was a revise of the original PCR series from 2007 and miraculously they developed os9 drivers.. probably the last ever midi controllers to feature drivers for mac os 9 from a proper manufacturer and not custom driver hacks)
http://lib.roland.co.jp/products/en/brochures/res/62223119/4134_EDIROL_Interface_Cat2007-1_72.pdfedirol PCR-1 
edirol pcr-30
edirol pcr-50
http://www.rolandus.com/products/details/582/downloadsedirol pcr-80
http://www.rolandus.com/products/details/631/downloads(the pcr-m series differs from the pcr-80 only in slight ways, it is a minor update providing a little bit more functionality in that u can more utilize the midi port routing in more versatile ways and the keyboard itself can act as a midi interface to an additional keyboard)
edirol pcr-m1
http://www.rolandus.com/products/details/736/downloadsedirol pcr-m30http://www.roland.com/products/en/PCR-M30/
http://www.roland.com/products/en/PCR-M30/images/image_02_L.jpgedirol pcr-m50
http://cms.rolandus.com/assets/images/products/gallery/pcr_m50_gal.jpghttp://www.rolandus.com/products/details/706/downloadshttp://www.rolandus.com/products/details/706/features/edirol pcr-m80
http://www.rolandus.com/products/details/707/downloadsevolution uc33-e a notable great controller for use with ableton live in os9 as it features its controls mapped out similar to the session view with 1 fader + 3 rotaries per vertical "track" but of course you are free to assign whichever control to whichever element within ableton
manual:
http://www.m-audio.ca/images/global/manuals/uc33e_adv_user_sgl_pg_eng.pdfevolution UC-16
evolution x-session
evolution x-session uc-17
evolution mk-449c
evolution mk-461c
evolution mk-425c
evolution mk-361c
evolution mk-361evolution mk-249/mk-249c
evolution mk-225c
m-audio RADIUM618 sliders, 8 knobs, 5 octaves, data slider midi in/out sustan pedal
m-audio RADIUM49 8 sliders, 8 knobs, 4 octaves, data slider midi in/out sustan pedal
m-audio OZONEmidi/audio interface, 2 octaves, 8 knobs, 2x2 24bit audio 96khz, XLRx1, 1/4" TSx1, headphone out
m-audio OXYGEN8
http://www.soundonsound.com/sos/jun02/articles/midimanoxygen8.asp
m-audio KEYSTATION PRO 88
m-audio KEYSTATION 49E
m-audio EKEYS 49
http://zkcd.net/_gfx/matos/dyn/large/m-audio-ekeys-49.jpg
