Though the market is still in its infancy, designers have already created a wide range of virtual instruments, from the silly (Pointy Heads' "Chicken Kazoo") to the sublime (Magnus Larsson's "Creation Gig Bundle"). For apps that recreate traditional instruments, there's quite a bit of competition. Drums and synths are the most frequently emulated, while guitars and, especially, basses are under-represented at ye olde iTunes Store.

There are many options for putting a trap set on your iPhone. jChicken's freeware "Drummer" has a clean aesthetic – a black five-piece set against a white background. The weirdly yellow cymbals imitate well their real-world counterparts, but the toms are badly out of tune and the kick is too quiet. Worse yet, there's too much latency to be able to hold down a beat. A far better choice is Benjamin McDowell's "True Drums 3D Lite." This option-loaded free kit gives you very low latency, tempo-adjustable record and playback, and the mighty spiffy ability to rotate the whole set. More than just a cute bonus feature, this enables you to play the kit from different angles. This may seem useless, but it's actually easier to execute the standard rock drummer beat while hanging out on the backside of the hi-hat stand. For $1.99, CrimsonJet's "Drum Kit" has zero latency and offers great sounds, but the visual layout is cluttered and its recording setup isn't terribly intuitive. For some, however, the lack of lag time between tap and thwap is crucial.

Finding the apps that are right for you depends on your desired application. Will you be playing your iPhone on stage? Recording a quickie demo to share with your bandmates? Or are you just hoping to get your creative juices flowing? All of these are viable options. For this article, I recorded an instrumental ditty by playing nothing but the apps I'd loaded onto my first generation iPod Touch. Because my apparently outmoded gadget (purchased way back in 2007!) doesn't come equipped with a microphone, I was unable to test drive Apptism's intriguing "Vocoder" ($0.99) or Sonoma Wire Works' highly rated "Four Track" recorder ($9.99). In a devastating blow, I wasn't even able to try out the "Chicken Kazoo."

These limitations are far from crippling, though. I began my on-the-fly composing and recording adventure with the Magnus Larsson's "Creation Gig Bundle," a suite of three music-making apps for a mere $4.99: a serviceable keyboard synth called "Destiny," a really nice eight-pad electronic drum kit named "DigiDrummer," and the biggest treat of the trio, "Bedrum." This 16-step drum sequencer worked perfectly for creating the foundation to my song. Crucially (for me), I didn't have to worry about holding down a steady beat. As with a real drum machine, I just punched a few buttons and quickly put together a workable drum track (the "real drums" sound I chose is hardly lifelike, but it sufficed). "Bedrum" allows up to four different tracks, so I added a pair of modified beats and threw in a fill.

Keeping with the spirit of using lowest common denominator technology, I recorded my song by running a 1/8" mini-jack cable from my Touch to my refurbished MacBook and into Garageband 3.0. Laying down a drum track then consisted of little more than setting up a new song in Garageband, hitting record, and then playing my programmed "Bedrum" parts. For a bass track, I turned to Mehmet Yonac's "miniSynth." For $1.99, you can't beat this faux vintage analog synthesizer, with its Kraftwerk-era sliders and waveform selectors. The program has one core sound, which can be manipulated in a limited number of ways. In the long run, this lack of selection might prove frustrating. For getting the job done, however, it's perfect. There's no bigger time killer than endlessly searching for that "perfect sound" amidst the 127 presets and infinite permutations that are available with most modern digital technology.

Being a guitarist, I was excited to lay down some rhythm and lead tracks, so I turned to Shinya Kasatani's 99-cent "PocketGuitar." Its four-fret, cherry wood design is attractive, very user friendly, and highly configurable. You can choose from four different guitars, electric bass, and even ukulele. Simply due to the size of the iPhone, many chords are difficult to play, and it's easy to let your fingertip slip a half-step off while you flex and contort your hand. It'd be wise to use "PocketGuitar"'s versatile alternate tunings and play as many open chords as possible. The app is better suited to soloing, especially once you select automatic plucking, string bending, hammer-ons, and pull-offs. Add some distortion and either chorus or delay, and shred away. I recorded an electro-acoustic rhythm track using two very simple chord changes and then laid down a really wet electric lead. Once you get used to the fact that "PocketGuitar" is not a real guitar, it becomes a fun and gratifying program.

Next, it was time to embellish. With its tinny sound, crowded display, and awkward functionality, Chen Ping's freebie "Real Violin Lite" isn't the greatest app, but I did stumble upon my song's melodic hook while fooling around with it. Ignazio Motisi's "iCongas Lite" (also free) is simple and perfect. The three conga heads are realistic both in appearance and sound. Plus, they're arranged in stereo! This made for a nice element within the final mix without even having to touch a panning knob. I also had a good time adding an extra tonal color with Chris Pavlou's "Kalimba Free," a nifty virtual kalimba (also known as mbira or African thumb piano). Finally, there's nothing better than having a theremin in your pocket (or are you just happy to see me?). The mighty developer Yonac snuck into my song yet again, thanks to his wonderful "Thereminator" ($2.99). As soon as it loads, you're ready to create '50s sci-fi movie sounds. Better yet, selecting options like "grid" and "note" helped me to quickly lay down an atmospheric track that was at least somewhat in key.

Because most iPhone music apps aren't velocity sensitive, very little mixing was required in order to turn these raw tracks into a finished Garageband song. I changed a few volume levels, whipped out some hard pans, and exported this MP3 lickity-split. The total time I spent on this recording project – learning how to get a usable sound out of each of these instruments, writing parts, recording them, and mixing the whole song – came in around four hours (half of which I spent re-recording tracks to compensate for my lousy timing).

So, while some of these apps may be lacking in sonic options, they compensate by keeping you focused on laying down tracks, or worrying more about the melody behind your songwriting than the awesomeness of your guitar sound. More than just a pretty iPod or a way to watch YouTube videos, your iPhone (or even your ancient first gen Touch) is a great tool for making music, wherever you are.