M-Audio has been making USB-powered MIDI controller keyboards for as long as anyone, and the Oxygen 49 (introduced in the Fall of 2009 and retailing at £99.99/ $149.99) is one of the more portable models in a family that also contains 25, 61 and 88-key models. It has full size keys which are more playable than you might have thought, and though they're not really designed for playing a symphony, are perfectly good for most everyday studio triggering operations. There's even a sustain pedal input on the rear panel, so you can be more expressive when playing piano and string parts. The USB connection carries data and power but there are no hardware MIDI ports. It's class compliant so requires no drivers.
The Oxygen 49 is portable and lightweight but has a sturdy build.
Most people are fairly familiar with this kind of device and the Oxygen 49 is a standard but solid MIDI controller : a staple of every studio from the smallest to the largest. It's lightweight too and sturdy, so could conceivably be gigged. As well as the standard mod wheel and pitch bend controls, you get eight knobs and nine sliders, which feel robust and well engineered. They are assignable of course to any parameter in your DAW, and the Oxygen family of controllers supports DirectLink mode, which is also known as HyperControl. The idea is that the controls can automatically map themselves to the most useful parameters in your DAW, after loading a template or setting it up as a control surface. There are also transport controls on the front panel for scrolling, recording, looping and playback.
This is a great idea, but unfortunately some of the DAWs that are supported are somewhat out of date, and newer ones don't recognise DirectLink. According to M-Audio's support page, Live 8 (and later) and Garageband '09 are supported, as is Logic 8 and 9.1 (in 32-bit mode) and Pro Tools 8. Some of these aren't the latest versions but they're not too old. Reason support is stuck at version 4 however, and Cubase at version 5.5, both of which are very long in the tooth now. I tried the auto mapping with Reason 6.5 and it did work to an extent but ignored all the newer devices and the new mixer, as I had thought it might.
Around the back it's as simple as USB, sustain and a power switch.
This isn't to say you can't use the Oxygen with the very latest DAW. You can use MIDI learn in the software and create your own templates and it works just fine. But this is time consuming and the automatic mapping templates need updating urgently to keep this feature relevant. In other regards this is a great controller, with transpose and octave controls and labelled keys for sending MIDI commands, and even the small LED screen manages to be useful. You get a copy of Ableton Live Lite too which is handy, and will get you started if you don't already have a DAW. This might also help to explain why Live support for DirectLink is still pretty good.
The Oxygen 49 is a good controller keyboard that's portable and affordable. It'll be even better when the DirectLink feature is updated to cover 64-bit and the most recent iterations of the leading DAWs.
web: M-Audio Oxygen 49