Boodler: Playing Soundscapes

First, make sure you have downloaded Boodler and installed it. (See Installing Boodler.) This command should play a little test melody:

boodler --testsound

If that doesn't work, none of the rest of this will.

Installing packages

Aside from that one test sound, all Boodler sounds and soundscapes are found in packages, which you must download and install from the Boodler web site. The package collection is at

If you take a look, you'll see a long list of files ending with ".boop". (For "Boodler package", right?) For example, indicates a package named "", version 1.0. Package names look like reverse domain names (or like Java package names). This makes it easy for people to add new packages without accidentally choosing the same name. org.boodler packages are core Boodler code; com.eblong.zarf packages were created by your humble servant. (To be sure, I also wrote the org.boodler packages. But I keep a distinction between work I do as part of the Boodler engine and Boodler soundscapes that I design.)

A package can contain sound samples, soundscapes, or both. But to facilitate sharing, most packages contain only one or the other. So when you want a soundscape package, you will typically have to download both that package and the sound packages it relies on.

(Some future version of Boodler will figure out these dependencies, find all the required packages, and download them automatically. Until that's written, though, you'll have to do it manually. We apologize.)

You download packages using the boodle-mgr script. To begin with, try this:

boodle-mgr install

This is a sound package, a collection of squawking crow samples. (It's filed in org.boodler.old because it was part of the sound library for Boodler version 1. I reorganized all those samples into org.boodler.old packages.)

You should see this output:

Package: org.boodler.old.crow    Version: 1.0
Title: Original Boodler crow collection

You have now downloaded and installed the package named org.boodler.old.crow. The files have been stashed in your home directory. On a Mac, this will be in ~/Library/Application Support/Boodler. On Linux or Windows, it will be a ~/.boodler folder.

Now install the soundscape which uses these crow samples:

boodle-mgr install

The com.eblong.zarf.crows package contains two soundscapes. Here's how to run the one named ParliamentOfCrows:

boodler com.eblong.zarf.crows/ParliamentOfCrows

You always run boodler by naming a package, followed by a slash, followed by the name of a soundscape in that package. You should hear a continual (and non-repeating!) stream of squawking noises. The soundscape will continue to play until you kill it, by hitting ctrl-C.

If you see a "package directory does not exist" error, then you didn't install one or the other of these packages. Install them both, and the soundscape should play.

Managing your packages

The boodle-mgr script can do much more than download packages. It is a complete toolkit for managing your package collection. Try this:

boodle-mgr list

The "list" command shows all the packages you have installed. You should see:

2 packages installed (ignoring multiple versions)

See the boodle-mgr reference for complete documentation of boodle-mgr. But it's worth mentioning a few tricks here:

The "contents" command shows the contents of an installed package:

boodle-mgr contents com.eblong.zarf.crows

This will list the sounds and soundscapes ("agent" means a soundscape) in that package:

Package: com.eblong.zarf.crows    Version: 1.0
Resources: 2
   ParliamentOfCrows [agent]
   SomeCrows [agent]

The "describe" command shows metadata about a package: title, author, licensing, what packages it requires. The "delete" command, unsurprisingly, deletes a package. The "help" command lists all the available boodle-mgr commands.

You can install a ".boop" file that you have saved locally, as well as installing by URL. You could have installed the org.boodler.old.crow package by downloading in your web browser, saving it as a file, and then typing:

boodle-mgr install org.boodler.old.crow.1.0.boop

Finally, boodle-mgr can be run as an interactive command-line tool. If you simply type boodle-mgr by itself, you will see a prompt, and you can type any of the above commands:

Welcome to Boodle-Manager. Type "help" for a list of commands.

> list
2 packages installed (ignoring multiple versions)

> describe com.eblong.zarf.crows
Package: com.eblong.zarf.crows    Version: 1.0
Metadata entries: 5
   boodler.main: main
   boodler.package: com.eblong.zarf.crows
   boodler.requires: org.boodler.old.crow
   dc.creator: Andrew Plotkin
   dc.title: The crows

> contents com.eblong.zarf.crows
Package: com.eblong.zarf.crows    Version: 1.0
Resources: 2
   ParliamentOfCrows [agent]
   SomeCrows [agent]

> quit

Passing arguments to soundscapes

Some soundscapes take additional options, which you can add to the command line after the soundscape names. If you just want to hear what the creator set up, you don't have to read this section. But options can let you customize your Boodler experience in all sorts of ways.

Here's an example. Install these two packages:

boodle-mgr install
boodle-mgr install

Tick is a very simple soundscape which plays a ticking clock:

boodler com.eblong.zarf.clock/Tick

But this soundscape also accepts a numeric argument, which modifies the speed of the ticking. The default value is 1; higher values speed up the clock, and lower values slow it down. Try:

boodler com.eblong.zarf.clock/Tick 1.3
boodler com.eblong.zarf.clock/Tick 0.7

You can try other values. But be moderate. Lower than 0.2 or higher than 5 will be distorted or difficult to hear.

(This is a simple resampling technique which changes both the pitch and the speed of the sound. Boodler does not offer fancier audio-editing capabilities like changing the pitch while holding the tempo constant.)

In fact the Tick soundscape accepts two options. The second is a "pan" argument, which controls where in stereo space the ticking seems to come from. 0 is the center, -1 is the left channel, 1 is the right channel. So:

boodler com.eblong.zarf.clock/Tick 1 0.75

...will generate ticking of the normal speed, but mostly (not entirely) shifted to the right channel. You may have to plug in headphones or stereo speakers to hear this effect.

You may notice that a negative value, for the left channel, doesn't actually work. It generates a confusing "no such option" error. This is because of the way Unix apps parse command-line options. You can work around it by either putting "--" before the soundscape name, or by putting all of the arguments in quotes.

boodler -- com.eblong.zarf.clock/Tick 1 -0.75
boodler "com.eblong.zarf.clock/Tick 1 -0.75"

(Yes, you can give pan values greater than 1 or less than -1. These shift the sound source past the left or right speaker. It will still come from that side, but fainter, because it is "more distant".)

What if you want to specify just the pan value, rather than both numbers? You can often give an argument by name. For example:

boodler com.eblong.zarf.clock/Tick pan=0.75

This gives a rightward stereo shift, as described above, but leaves the speed at the default value (1). The speed argument is called pitch, so you could also do:

boodler com.eblong.zarf.clock/Tick pitch=0.75 play a slow, center-field sound.

(How do you know what options a soundscape takes, and what they're named? The Tick soundscape accepts pitch and pan, but other soundscapes want different arguments, or none. Unfortunately, there is no current way to do this, except for examining the source code in your package collection. A future version of boodle-mgr will allow you to examine a soundscape and list its options.)

Passing sound arguments to soundscapes

We've seen soundscapes make use of sounds from other packages. Some soundscapes accept sounds as arguments. Here's a handy trick; install this package:

boodle-mgr install

Then try:

boodler org.boodler.old.clock/clock_cuckoo

This plays a "cuckoo" sample from the org.boodler.old.clock package you installed above. (If you see an "unable to load" error, go install it.)

The OneSound soundscape can play any sound file from any Boodler package you have installed. Use the "contents" command (in boodle-mgr) to list the packages you have, and explore the sounds that are available. OneSound also has pitch, volume, and pan arguments, so you can alter the sounds as you play them:

boodler org.boodler.old.clock/clock_cuckoo pitch=1.5 pan=1

The package has several tools for playing particular sounds. SoundSequence lets you play several sounds in a row:

boodler org.boodler.old.clock/clock_tick
    org.boodler.old.clock/clock_chime org.boodler.old.clock/clock_cuckoo

(That should be typed all on one line, by the way.)

RepeatSound plays a single sound over and over. You could say:

boodler org.boodler.old.clock/clock_tick

...and, in fact, this is essentially how the com.eblong.zarf.clock/Tick soundscape works.

Passing soundscapes to other soundscapes

Some soundscapes make use of other soundscapes -- not just sound samples. Some soundscapes accept other soundscapes as arguments. This lets you play all sorts of interesting tricks.

Install these five packages. (You may have already installed the crows from the earlier example.)

boodle-mgr install
boodle-mgr install
boodle-mgr install
boodle-mgr install
boodle-mgr install

The crows and the basicwind give us a nice assortment of Halloweeny soundscapes:

boodler com.eblong.zarf.crows/ParliamentOfCrows
boodler com.eblong.zarf.basicwind/Windstorm

It would be nice to play the crows and the wind simultaneously. You could learn soundscape design and write a soundscape that blended them -- and I encourage you to do that. But the capability is already available, in org.boodler.manage/Simultaneous:

boodler org.boodler.manage/Simultaneous

(That should be typed all on one line.)

The Simultaneous soundscape takes a list of soundscapes as arguments, and plays all of them. You can even include arguments to the soundscapes on the list:

boodler "org.boodler.manage/Simultaneous
    (com.eblong.zarf.basicwind/SteadyGale 0.8)"

SteadyGale takes a pitch argument, and this example lowers it to 0.8. The parenthesized list wraps up the soundscape and its arguments, and presents them to Simultaneous as a unit. Sadly, Unix treats parentheses specially, so you have to quote all the arguments, or use a lot of backslashes. (The "--" trick won't work here.)

Some other varied examples:

boodler org.boodler.manage/Sequential 6 8 2

As you might expect, Sequential plays several soundscapes in sequence -- in this case, it alternates between the crows and the wind. The numeric arguments tell it to switch every 6 to 8 seconds, with a two-second crossfade.

boodler org.boodler.manage/Limit com.eblong.zarf.basicwind/Windstorm

Limit plays a soundscape for a limited time -- 30 seconds, by default -- and then cuts it off. (Notice that when all soundscapes have ended, Boodler shuts down by itself.)

boodler org.boodler.manage/Limit com.eblong.zarf.basicwind/Windstorm 10 5

The two arguments are the length of time to play, and a fadeout time (in seconds).

boodler org.boodler.manage/VolumeModulateAgent com.eblong.zarf.crows/ParliamentOfCrows delta=0.6

VolumeModulateAgent plays another soundscape, but shifts the volume up or down roughly once per minute. If you let this run for several minutes, you'll hear the crows fade in and out a bit.

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