Lets start with the bad news, Xewton Music Studio is a $20 iphone application. That is a lot of money on a platform that offers an almost infinite amount of free and under $2 apps. That being said this thing is a beast and in a world that seems to be in a drunken race to the bottom, I will gladly stand on the top and give Xewton my hard earned 20 bucks.
iPhone and iPad apps tagged "music sequencer."
Melodica Light and Sound Combine for Simple Music Creation
Melodica presents a 16 by 10 surface where the length represents the 4 bars of a 4/4 beat and the height is a set of 10 notes that all harmonize well together. Anyone familiar with arppegiators or sequencers will find themselves at home using the software's interface.
FourTrack is a Big Step in iPhone Music Production.
When developer Sonoma Wire Works set out to create a multi-track recorder for the iPhone, they enlisted the help of Retronyms, creators of the best selling Recorder iPhone app. Together they built FourTrack, the closest anyone has gotten to creating a rich-featured, studio-quality multi-track recording app for the iPhone.
Synth Round-Up: Synthesizers Break Free from the Studio on the iPhone
Musicians of all calibres, from mom's basement amateurs to true prodigies, can now find the software they need to make music on the go on their iPhones, whenever and wherever they want. But with so many options, it's often hard for people to figure out which app suits them best.
synthPond makes for beautiful sound ripples.
SynthPond gives people with no previous knowledge of music the ability to create beautiful, ambient, soothing synth loops. It uses a color-based notation system, a sequencer referred to as color sentences and a series of concentric "pond-like" circles with resonating notes placed inside them as a panning and timing system.
Noise.io Pro is First True iPhone synthesizer — for Professionals
This is it. The first full-fledged synthesizer available for the iPhone.
Noise.io Pro features everything you would expect from a synth including a large and expandable preset bank, a powerful sequencer, a rich ESFM synthesizer processor, (an enhanced version of the traditional Frequency Modulation) along with all the bells and whistles you can expect from any professional synths.