Let’s write a beat that (re)writes itself. I’ll start with the hi-hat because... why not.
I’m going to use a few techniques to vary the pattern, emulating an improvising drummer. First, I'm going to track two bars’ worth of hat and each bar is going to be a different length.
<sequencer-blam bpm="90">
<track-blam to="#hat">
<bar-blam s="1 0 2 0 ? ? ? 0"></bar-blam>
<bar-blam s="1 2 0 0 ? 0 ?"></bar-blam>
</track-blam>
</sequencer-blam>
This gives us an unusual 15 quarter-beat phrase. When I later combine this with more common measures of 8 quarter-beats, I get polymeters: compound patterns made from multiple time signatures playing at the same tempo. This is my favorite way to quickly generate complex and unexpected patterns. An 8 quarter-beat pattern and a 15 quarter-beat pattern make a combined 120 quarter-beat pattern (8 ⨉ 15).
Note the s notation for the bars:
<bar-blam s="1 0 2 0 ? ? ? 0"></bar-blam>
<bar-blam s="1 2 0 0 ? 0 ?"></bar-blam>
Positive integers reference samples by index, as loaded by an associated <bank-blam>...
<pads-blam id="hat" choke out="bus">
<bank-blam>
<sample-blam src="/static/sounds/kit-garage/hat/01.mp3"></sample-blam>
<sample-blam src="/static/sounds/kit-garage/hat/02.mp3"></sample-blam>
<sample-blam src="/static/sounds/kit-garage/hat/03.mp3"></sample-blam>
</bank-blam>
<blam-blam prop="detune" value="-25~25"></blam-blam>
</pads-blam>
... whereas the ? cipher means “pick any sample”. The way the sample-based instrument, <pads-blam>, is designed, a random sample but never the previously played sample will be selected. Unless there’s only one sample given, of course.
In this case, the three samples are a closed hat (1), another slightly different closed hat for variety (2) and an open hat (3). Note <pads-blam>’s choke attribute. It ensures the previous sample/sound is silenced when the next one begins playing. This is critical for sequencing hi-hats, since the open hat must be forced shut to be played closed.
In addition, a <blam-blam> element is incorporated to fluctuate the tuning of each sample as it is played. This element listens for an event from <pads-blam>, scheduling a sound, and assigns a value to the detune property/audioParam between 0 and 60 cents.
<blam-blam prop="detune" value="0~60"></blam-blam>
This adds additional tonal variety, making it sound somewhat like we are dealing in more than three samples.
Finally, a <dial-blam> is proffered for controlling the <sequencer>’s bpm. Since HYPERBLAM sequences compositions in real time, you can change the tempo on the fly, using either an interface like <dial-blam> or automation using <blam-blam>.