Whoever thought the iPhone would become a platform for music creation?  From full blown professional music apps like Beatmaker, which allow producers to sample and program beats – to  experimental works of art like Brian Eno’s iPhone app, Bloom, which helps users zone out to plush soundscapes that react when their fingers touch the screen.  The iPhone has become a platform for digital instruments.

Smule, a startup company based out of Menlo Park, Ca., which was behind the highly popular iPhone app, Ocarina, has taken the next step in iPhone music gaming with its new application, Leaf Trombone World Stage.  

Here's some key features.

Leaf Trombone is similar to Ocarina, in that it plays as a music instrument where the user blows into the iPhone microphone while playing notes on the screen to create melodies.  Overall, it takes these same basic elements from Ocarina, but boosts them a step further by adding live multiplayer, judging and training.  It’s also changed the sound to something less serious and more, light hearted in comaprison to the Ocarina.

Beside the whole, “iPhone as an instrument,” concept that Smule brought to us with Ocarina, it also implemented social elements. Users could actually see and hear people from around the world playing their virtual Ocarina’s in real time.  

Leaf Trombone upgrades these social elements by creating a World Stage, where users can judge and rate each other using 1-10 scales, comments and emoticons.  These ratings are then added to the performer’s overall ranking.  Judges in turn receive tokens which they can use in order to perform on the World Stage.

Also, with Leaf Trombone, users can now learn how to play songs within the application.  This was a feature Ocarina didn’t integrate – user’s had to check out a separate Web page to learn new songs.  The interface for learning in Leaf Trombone is reminscent of Guitar Hero, where notes come forward on the screen to the player, and they have to hit them in the right order and sequence to succesfully play the song.

Smule says the inspiration for the app came from traditional Chinese leaf instruments.

In the end, if you were a fan of Ocarina, like I was, you’ll pretty much really like Leaf Trombone.  Unfortunately, don’t expect the same peaceful sound Ocarina generated, instead Leaf Trombone is, well, much more nasal and trombone-like.  The application currently sells for .99 cents in the Apple App Store.

Below is a Leaf Trombone rendition of the 80's classic "Tainted Love," by Soft Cell.  Let's see what you think of it.

A little on Smule as a business.  The company has raised almost $5 million since its founding in 2008.  With five other iPhone apps already released, Smule says is currently revenue generating.