Michael J. Wilson - Music 256a Final Project

sequins Version 1.0

By Michael J. Wilson (mwilson@alumni.caltech.edu)

Thank you for choosing sequins, your gateway to the wonderful world of spectral modeling synthesis sampling step sequencers!

BUILDING:

Type 'make' to build the project.

The project depends on several libraries:

• sndfile
• gsl
• gslcblas
• QtGui
• QtCore
• pthread

It also requires Jack to operate. You may be able to build it with native Alsa support but I haven't tested that. Options are available in the makefile.

RUNNING:

Start Jack, then run release/sequins. You will be presented with a GUI application.

There are various controls near the top of the application dialog:

• Play - Starts playback of sequences
• Stop - Stops playback
• Tempo - Adjusts playback speed (from 1 to 800 BPM)
• New Track - Allocates a new track (you may allocate as many as you wish)
• Quit - Close the application

After hitting New Track, a new track will appear in the lower section of the program (you may want to resize the program window to see more of the track).

• (Text area) - For making a note of the purpose of this track
• Close - Close the track, discarding its sequence and recorded sample
• Mute - Toggle the mute status of this track
• Record - Record a sample for this track. When the button is pressed once it turns red and recording is active. When it is pressed again recording stops and the recorded sample is processed.
• Matrix edit - Left-click here to set pitches, right-click to remove them

So what's neat about this? Well, you can make various tracks, record sounds into them, and then play them back at various pitches (via the matrix editor) and speeds (via the tempo control). Unlike some similar programs which adjust the playback speed of the samples to change their length or pitch, this program uses spectral modeling resynthesis via libsms (http://mtg.upf.edu/static/libsms/) to do the pitch shifting and time stretching. That means that pitch and length may be adjusted independently of each other. Play around with it and see what you think :-)

NOTES:

For copying information, please see the file COPYING included with this package.

I am grateful to Rich Eakin and Xavier Serra for libsms, Gary P. Scavone for RtAudio, and the Qt team for the Qt Development Framework.

And of course to Ge Wang, Nick Bryan and my classmates for their encouragement and support during the construction of this program.

MISC:

• Proposal
• Development Log