Apple released its two new “flagship” iPad apps today, and much to the surprise of original iPad owners, GarageBand is available for both the iPad 2 and the original iPad. While last year’s model doesn’t make the cut for iMovie, GarageBand goes for a measly $5 in the app store starting today. While it might not be as snappy and fluid on the original model as it is on the iPad 2, it’s still an incredible app for the money and a giant step forward for tablet app interfaces.

GarageBand for iPad offers eight tracks of recording and mixing, as well as built-in loops, standard software instruments including guitar, drums, bass, keyboard, and a sampler, and Apple’s new “smart instruments,” which makes creating great-sounding tracks and loops almost effortless. The “Smart Guitar,” for instance, puts the actual strings of a guitar on the screen that you can strum and pick, and it’s quite surprising how real it feels. You can switch the guitar to “chords” mode if you aren’t exactly musically inclined, and simply tap buttons to play chords and change the style of the guitar around. Whether you’re a guitar virtuoso or just learning, you can use the smart guitar to record a guitar track for your song in no time.

There are also several different modes for creating drum loops — one which puts a full drum kit on your screen that you can tap to play, and one which gives you a grid that you can drag instruments on to to create the loops. The grid allows you to control how loud and how “complex” each instrument sound is, but beyond that the results seem to be pretty random. There’s not a standard drum machine layout here that allows you to customize your own loops on the grid; you’re either playing the virtual drum set with your fingers or surrendering to the limited control of the grid mode.

Other instruments in GarageBand include a standard keyboard, an “amplifier” mode where you can actually plug in a real guitar and use the iPad as a virtual effects pedal, and a sampler mode that allows you to record sounds and manipulate them with the on-screen keyboard. If you’re not interested in the fancy virtual instruments, a line-in mode exists as well that lets you lay down a track from the iPad’s audio input.

Once you’re done recording your tracks, the song layout view allows you to control the mix and positioning of the recorded tracks as well as add loops from Apple’s loop library and preview your track before its done. Any GarageBand for Mac user will be familiar with this screen, and the iPad makes it even more intuitive. You can swipe the track controls off and on the screen, drag tracks around with your fingers, and tap to look through the instrument loops. GarageBand for iPad allows for a surprising amount of control over your tracks, and the app could easily be used by a band to do quick demos on the go.

Overall, GarageBand for iPad is a huge leap forward for tablet applications. It’s pretty incredible that a device which so many had dismissed as “never going to be useful for work” has evolved to the point that there is an app this powerful in only a year. On the original iPad GarageBand does have its limitations, however, meaning that loading times were very noticeable and some of the dragging effects and transitions in between different areas lagged somewhat. It’s obvious that this app was designed with the iPad 2 in mind, but it’s really nice that Apple decided to not leave out its 15 million original iPad owners. If you’re a music junkie, band member, or even just like to tinker with the newest apps, at $5 GarageBand is a must get.