When musicians first laid eyes on the iPad, they immediately recognized its huge potential as a music-making machine. The versatility of the touchscreen quickly gave rise to a bevy of synths, drum machines, multitrack recording apps and otherworldly, touch-sensitive instruments. And while making music on the iPad is still mostly about the apps -- Animoog, Korg iElectribe, NodeBeat, GarageBand, Sunrizer, JazzMutant Lemur -- the tablet becomes even more useful if you can plug other stuff into it. At first, we only had the ability to plug in guitars and microphones to record songs. But now, ever since Apple added support for the CoreMIDI framework to iOS and introduced the Camera Connection Kit, we can plug in a variety of keyboards, drum pads and other hardware to control our apps. Instead of tapping the touchscreen to make a noise, you can play a chord, press a key or twist a knob. Here's our guide to this season's latest gear for iPad musicians. iPad Camera Connection Kit, $30 In order to use most music-making devices with an iPad, you've got to get one of these. Apple's $30 device (the square-ish white adapter in the photos above and below) essentially turns the iPad's dock connector into a USB port. The company calls it a "Camera Connection Kit" because that's what most consumers are going to use it for. But musicians can use it for much more than holiday snaps. USB keyboards, hardware controllers, preamps, headphones, digital-to-analog converters -- this little dongle is your lifeline to hundreds of audio toys. Photos by Ariel Zambelich/Wired

iConnect MIDI $180 When Apple's CoreMIDI framework first showed up in iOS in late 2010, it gave iPads the ability to connect to MIDI instruments. So now you can plug all of your favorite MIDI keyboards, drum pads, MIDI guitars or controllers into your iPad and use those instruments to play the sounds generated by your iOS apps. Of course, to do this, you'll need a piece of MIDI connection hardware to hook up your gear. In our opinion, your best bet is the iConnect MIDI. It's a tiny I/O box with a ton of versatility. It has traditional 5-pin DIN MIDI ports (two inputs and two outputs) as well as two mini-USB ports and a full-sized USB host port that can accept a USB hub. In all, you can connect up to eight devices using the USB hub port. A wall wart is required -- all that device power has to come from somewhere -- but the iConnect MIDI has very low latency and can connect just about any device to any app that supports CoreMIDI.

Avid M-Audio Keystation Mini 32, $80 There are dozens of keyboard controllers you can use to drive a music app running on your iPad. One standout from the latest crop of controllers is the Keystation Mini 32 from M-Audio. Most controllers have one or two octaves, but this one has two and a half, for a total of 32 keys. And yet it's still very compact -- about 17 inches long, so it will fit in a laptop bag or a backpack easily. It draws all the power it needs from the iPad using the Camera Connection Kit, adding to its portability. Actually, the Keystation Mini is so small, the keys can be a little tricky to play properly. But most users will be able to comfortably use both hands to play more complicated pieces given a little practice. The knob and three of the buttons on the left edge are programmable, as is the key velocity, so the Keystation Mini can double as a surprisingly accurate drum machine controller.

Korg nanoPad2, $60 The new NanoSeries2 of controllers from Korg gives you a few more options for controlling iPad apps. Our favorite is the nanoPad2, a 16-pad controller that's great for triggering drums or samples. Riding shotgun is an X-Y pad similar to what's found on Korg's Kaossilator hardware and its iKaossilator app for iOS -- Use the touchpad to layer on effects and filters as you tap out beats, notes or samples with other hand, or use it to play pre-programmed, multi-note phrases. As with the other controllers in Korg's nanoSeries2 line, the nanoKey2 and the nanoKontrol2, the nanoPad2 hooks into the iPad via a Camera Connection Kit. But Korg recommends also running a powered USB hub if you're going to be using its nanoSeries2 controllers for "an extended period of time."

Alesis iO Dock, $200 If you're a true multi-instrumentalist (and maybe you sing a little as well) the Alesis iO Dock is a decent choice for plugging a variety of gear into your iPad. There are a plethora of inputs -- quarter-inch inputs for guitars, basses and other electric instruments, powered XLR inputs microphones, and both USB and 5-pin MIDI interfaces for digital keyboards and controller hardware. There are also stereo outputs for connecting to a mixer or PA system, and a headphone jack with a separate volume control. The whole assembly is wedge-shaped, and your iPad snaps onto the top of the wedge so it sits tipped toward you. It's a useful piece of hardware for producing tracks in a studio, but it's made of cheap plastic, so you'll have to treat it gently if you intend to gig with it. Also, it requires an AC adapter at all times. Another note: Alesis designed the iO Dock for use with the first iPad. If you have an iPad 2, be sure to get the version that ships with the plastic shim so your iPad 2 sits properly inside the dock. If there isn't a shim in the box, Alesis will mail one to you -- or you could just fashion your own.

CEntrance AxePort Pro, $150 Recording some tracks on your iPad? Rather than rely on a cheap accessory to plug in your instrument, take a step up to the AxePort Pro. Inside this rather nondescript aluminum tube lies a pro-grade, 24-bit/96 kHz preamp. Plug in your guitar, bass or pretty much any electric instrument and let the preamp sweeten up your tone (The company also makes a similar microphone preamp). We were able to get a warm, natural tone out of a variety of instruments. We used the AxePort to record some tracks to GarageBand, and it did wonders to improve the sound of some of GarageBand's built-in effects (especially on the bass). And a bonus: The AxePort Pro doubles as a headphone amp, so you can monitor your session without any latency problems. One caveat -- it's a USB device, and it connects to the iPad using the USB Camera Connection Kit. But Apple's little white dongle doesn't provide enough power to run the AxePort Pro's preamp, so you have to use a powered USB hub (or some other powered USB device, like the iConnect MIDI) in between the iPad connector and the AxePort Pro to provide power. You can also use a portable USB juice pack. If you use it with a regular laptop or desktop, no additional power source should be needed.

Apogee Jam, $100 Here's another dongle made for guitarists and bassists, a dead simple interface for connecting to GarageBand, Logic or any iOS app. The Apogee Jam doesn't have the sweet-sounding preamp or the on-board headphone amp of the AxePort Pro, but it's $50 cheaper and simpler to use. It doesn't require any external power or a Camera Connection Kit -- all of the cables you need come in the box. The controls are very simple, too. There's a gain control knob on the side, and a single status LED that doubles as a peak indicator.

AmpliTube iRig, $40 and up This little device from IK Multimedia does more than just connect your guitar to your iPad -- it also puts the iPad to use as a virtual guitar amp and effects station. The iRig hardware interface is a simple box that plugs into the iPad's headphone jack. After connecting your guitar and a pair of headphones, fire up the AmpliTube app to build a virtual rig of amps, speaker cabinets and effects. The app also comes with an 8-track recording studio that's fairly easy to use. The iRig is $40, the AmpliTube app is $20, and the fancier effects are available as in-app purchases. The selection of available amps and effects is vast, but buy more than a few (each priced at $3 and up) and things can get pretty expensive. However, the setup has a very low latency and the sound is great, especially the digital models of the classic tube amps. Also, the bass sounds are solid -- much better than we expected from an iPad app. If you're more Keith Jarrett than Keith Richards, iRig also makes a MIDI interface.