Electronic Guitar: iPad Apps for Guitar

Four Must-Haves for Expressive Processing with iOS
Image placeholder title

Last month, I explained how to create a hybrid guitar-processing setup using apps on an iPad with Ableton Live on a laptop. Of course, the apps I included in that column are but a tiny portion of the available music-related products for iOS.

This month, I’ve chosen four apps that, as a guitarist, I find are the most useful. One is an important utility app, while the others are geared toward sampling and signal processing.


Fig. 1. Audiobus for iPad and iPhone

Image placeholder title

Once you’re hooked on iOS apps, you’ll want to use more than one at a time. Audiobus provides a kind of virtual pedalboard/switching system that allows you to use multiple music apps at once, by passing audio and MIDI between them (see Figure 1). The latest version lets you adjust levels and panning for all audio sources. And with the Audiobus Connection Panel, you can cue playback, recording, and more, without having to call up the individual app. Install Audiobus Remote on your iPhone, and you can switch app screens on the iPad and perform many of the connection-panel functions at a distance.


Fig. 2. Samplr’s keyboard mode lets you re-pitch your sample.

Image placeholder title

Samplr makes full use of the iPad’s touch functionality to trigger and manipulate samples, whether pre-recorded or captured as you play (see Figure 2). You can record your guitar into any or all of its six tracks, where the app automatically slices the audio into sound bites. For example, record a chord progression and use your fingers to play each chord separately, in any order, even with the audio reversed. You can also play multiple chords at once, freeze them, and use the arpeggiator function to move among them. A sustaining distorted-guitar note can be turned into a bass pattern by dropping the sample an octave within the app and applying rhythmic slicing. All this merely scratches the surface of what this amazing app can do.


Fig. 3. In this setup, pushing play on track 3 of iDensity will process my guitar in real time, whereas the other tracks will only play when I scrub my finger across the audio file.

Image placeholder title

This app will let you enjoy the unique sound of granular processing (see Figure 3). As with Samplr, you can load samples into six slots but, unlike in that app, you can also process your guitar in real time six different ways, simultaneously. You can record any of the tracks and, once it is captured, change the pitch of the recording with a separate virtual keyboard for each track. And that’s merely a fraction of iDensity’s processing possibilities.


Fig. 4. In Borderlands you can simultaneously process one track with two clouds, and two tracks with one cloud.

Image placeholder title

This iOS effect offers even more granular processing fun, combined with Samplr-like touch controlled functionality (see Figure 4). As with iDensity, you can record your guitar or process it in real time, but unlike in the other two sample processing apps you can record as many tracks as you like. Double tapping on a recorded track creates a circle, called a “cloud,” that processes the audio multiple ways within its circumference. You can move the cloud along the track to process different parts of the sample or pull it off to stop playback. You can put multiple clouds on one track, and tracks can also be pushed around with your finger so you can layer multiple tracks under one or more clouds. Borderlands will record the movement of the clouds as you push them around, as well as parameter changes within each cloud as you make them. Playing your guitar in real time through two moving clouds as parameters are changing is something you need to experience.