I've been working on a <a href="http://www.casperelectronics.com/finished-pieces/sequencers/step-sequencer/">step sequencer</a> design for a while based on the <a href="http://www.doctronics.co.uk/4017.htm">4017 decade counter</a>. I've finally gotten around to building a working prototype!<br>
I posted the schematics <a href="http://www.casperelectronics.com/sequencer-update/">here</a> a few months ago.
You can also find them on the <a href="http://www.casperelectronics.com/finished-pieces/sequencers/step-sequencer/">step sequencer page</a> which I just uploaded. 
<a href="http://www.casperelectronics.com/images/finishedpieces/sequencers/S3600028_1.JPG"><img src="http://www.casperelectronics.com/images/finishedpieces/sequencers/_S3600028_1.JPG" width="400" height="300" alt="" title=""  /></a>
I also uploaded an awesome sound recording of the <a href="http://www.casperelectronics.com/finished-pieces/sequencers/step-sequencer/">sequencer</a> in action. The recording was made using the sequencer to trigger three different synths.<br>
--A <a href="http://www.casperelectronics.com/finished-pieces/casper-sk-1/">casio SK1</a> was used to make the melodic sounds. <br>
--and I had that running through an <a href="http://www.casperelectronics.com/images/finishedpieces/echo/S3600062.JPG">echo circuit</a> I've been working on for a while
--the bass drum beat was made with a Korg MS20.<br>
--The other rhythmic tones were made with a Paia modular synth<br>
The casio has been modified to allow an external trigger to activate the recorded melody play back feature. So I can record a melody into the SK1 and play it back one note at a time every time i send a pulse to the new "playback" jack.
 <a href="http://www.casperelectronics.com/images/finishedpieces/sequencers/S3600032_1.JPG"><img src="http://www.casperelectronics.com/images/finishedpieces/sequencers/_S3600032_1.JPG" width="400" height="300" alt="" title=""  /></a>
<a href="http://www.casperelectronics.com/finished-pieces/sequencers/step-sequencer/">Here's</a> the step sequencer page.<br>
The recording is at the bottom of the page.