I'm just learning how to use midi. It's a completely different language and takes some time (at least for me) to learn.
A friend of mine gave me her old Yamaha DX21 keyboard which has midi I/O. I've noticed that on some of the new midi keyboards out there, they only have a midi out like this one -
(link to an old M-Audio USB/MIDI Controller keyboard)
Why is that?
As always, thanks for your helpful response.
It is because those keyboards are simply MIDI controllers and they don't have any sounds of their own, so there is no need for a MIDI IN port for them since you can't use them as a sound module.
In fact, most of the time you don't even need the MIDI OUT port on these devices since, at least in the studio, you'll have them hooked up to a computer running sequencing software and the MIDI data will actually be sent to the computer via the USB connection. But, the MIDI out port is handy if you want to use the controller live to control some rack mount sound modules or other synths, or to connect to an old computer that you've installed a MIDI interface on and have no USB ports available.
Many of those MIDI controllers do have software that allows you to save different configuration presets for the buttons, knobs, and faders, and load those into the controller at a future date, but this is done via USB and MIDI ports are again not needed.