Source Selection

Curtis works by playing back grains from a source sound recording. This bar shows the currently loaded source recording. You can touch various regions along the bar to scroll to different regions of the source. Depending on the length of the source, you may be able to pinch the bar to zoom in and out a bit as well.

Load Save Record

LOAD lets you load a new sound to manipulate with Curtis. SAVE lets you save the sound currently being manipulated. RECORD lets you use the iPad microphone to record new sounds which can be manipulated or saved for later. To prevent accidental triggering of this record mode during a performance, the button is hidden under a safety slider. Simply move the slider as indicated by the arrow, and tap the newly revealed RECORD button.

Source Area

Here is where you can interact with the source, selecting grains to play. A single touch in this area lets you pick which part of the source will be used to generate grains and how big the grains are. Moving along the length of the source chooses the grain position, while moving across it chooses the grain size. The cyan cursor indicates both size and position.

A two-finger pinch in this area determines a range in the source from which grains will be randomly chosen. The area is indicated by two cyan range indicators across the length of the source. This will give a more chaotic and noisy sound with less tone. To return to single source point mode, pinch to create a tiny range which will snap to zero, whereupon the range indicators disappear.

Chroma and Scratch

If CHROMA is enabled, grain size is quantized to standard tuning frequencies, otherwise a wider range is available. If SCRATCH is enabled, dragging along the length of the source is more akin to scratching a record.

Slew

The SLEW modes determine if grain size and grain position snap to new settings or if they drift smoothly. This functions similarly to a portamento control when slewing grain size and like a wavetable morph when slewing position.

LFO XY Pads

These pads allow you to automatically wiggle the size and position of the grains being generated. The long dimension determines the speed of the wiggle, while the short dimension determines its intensity.

Keyboard

With CHROMA mode enabled, you can also use this keyboard to determine grain size. Only one note at a time can be played. Dragging the keyboard moves it, allowing you to play at different octaves. Depending on the source material, grain size, and position in the source, the notes you play may be more or less tonal.

Hold

With HOLD mode enabled, Curtis endlessly plays back grains from the selected position or area at the chosen size, with possible modulation from the two XY PADS. With HOLD mode disabled, the ENVELOPE will determine note onset and decay as you tap the SOURCE AREA or the KEYBOARD.

Envelope

Although you can adjust ENVELOPE settings in any mode, they only have an effect on the sound when not faded out. The ENVELOPE has no effect in HOLD or SCRATCH mode.

Envelope controls work like those found on synths of yore. ATTACK determines how quickly a note fades in, DECAY how quickly it fades to the SUSTAIN level, and RELEASE how long the note is held once you stop touch the KEYBOARD key or SOURCE AREA.

Main Mix

The GAIN slider controls the volume of the sound by increasing the source gain. You will see the source grow or shrink as you adjust this. PITCH will detune the output sound. The middle position applies no detuning. ECHO LEVEL controls the amount of echo mixed in, while ECHO TIME controls the length of the echo.

Performance Record (new in version 2.2)

Starts recording the sounds you are making with Curtis. These recordings can be saved as WAV files in the Documents directory of the app. You can access them through iTunes, by connecting and selecting your device, and clicking the Apps tab.