At the Sounding Edge: Introducing KeyKit
First, we are going to run two simple tests to become familiar with some more KeyKit interface conventions. Open KeyKit's main menu again and then open the Tools1 submenu. When the menu seen in Figure 1 appears, select the Riff item. The menus vanish now, and the normal cursor becomes what is called a sweep cursor. Click and drag the sweep cursor to define and size the Riff window and release the mouse key. The area outlined by the cursor now is filled with the contents of the Riff tool. Open the tool's More menu and select Load From File to load a standard MIDI file into Riff. The results should look something like Figure 3. The Riff data display window is similar to the typical piano-roll display found in many MIDI sequencers, with pitch represented by the vertical axis and duration represented along the horizontal. Toggle playback with the On button or start play by left-clicking anywhere within the data display. Right-click anywhere within the display to stop playback. KeyKit has many other playback options, but we are going to confine this simple example to the simplest methods.
So KeyKit can load and play a MIDI file; that's nice. Now, let's look at something more substantial. Delete the Riff tool and then open and size the Kboom tool from the Tools1 menu. Kboom looks like a typical virtual drum machine (Figure 4), but its modest appearance conceals an interesting and useful set of tools within its More menu. As with most software rhythm programmers, Kboom lets you add and remove beats from the grid by clicking on a grid point. You could select, however, one of the Random items from the More menu and let Kboom program itself. This feature is handy for those of us who like to sculpt patterns from randomly generated parts. Kboom's other musically useful features include Shift and Transpose functions, but you'll have to check them out yourself. It's time to move to a more advanced KeyKit example.
The Group tool from the Tools1 menu looks much like a track-oriented MIDI sequence editor. After loading a MIDI file into Group, you can view and edit its data in merged and per-track displays (Figure 4). But Group soon begins to lose its similarity to conventional MIDI sequencers, especially in its Edit functions. Scrolling through Group's Edit menu reveals some unusual functions and processes, such as BeatStep, Chordize, Evolve, Permutate and Stutter, along with more familiar sequence editing tools, such as Flip (invert), Reverse and Scale. Many tools have nested submenus for finer control over their processes. Figure 4 shows the Group tool at work with its Edit/Randomization menu unfolded to the detail level of its white noise generator.
The lighter-colored events in the Merged and Trk 2 displays were selected with the Pick function in the Trk 2 menu. To pick something in KeyKit isn't merely a process of simple selection. Trk 2's Pick menu includes items for selecting by various event characteristics, including duration, volume and channel; by opposite state, such as making unselected events become selected and vice versa; and even for random selection.
Group is a powerful tool. Events can be selected variously per track, and an edit or series of edits can be performed on the picked events. Then, you can flip the pick status for all events and perform another edit or edits on the newly picked events. At any point in this process, you can save your work as a standard MIDI file, and you can save your page layout as a snapshot from the Page submenu.
You also can snarf the outcome of your edit session at any time. Snarfing is KeyKit's term for pasting a tool's MIDI data to a global data clipboard, making the snarfed data available to any other tool--you can run multiple tools. In the Group tool, snarfing is selected from each track's label menu, the buttons labeled Merged, Trk 1, Trk 2 and so on. Notice that you can choose to snarf all or only the picked events within a track.
KeyKit's Markov Maker (in the Tools2 menu) processes a MIDI file's data through a set of constrained variations known as a Markov process. This tool analyzes input and formulates output according to user-defined values called Set Sim and Make Sim. The Sim here stands for similar. Markov processes yield results that are closely related variants of the original input, making them especially useful for composers wanting to retain more-or-less strong identities between variations.
Click on the Orig button to access the Set Sim parameters. These values determine the analysis window size and temporal increment, the interval at which the window moves through the data. Click on the Sim button to set the Make Sim value; higher values yields longer sims. The Sim data display then fills with the results from the combination of input/output values (Figure 6). Toggle playback with the mouse buttons as described above, and remember to save your work.
No experimental music toolkit would be complete without an image-to-sound converter, and KeyKit's PictSweep tool completes the kit here. PictSweep is another apparently simple tool that includes a respectable set of useful editing functions. Its More menu includes choices for scale selection, setting the key, thinning the color conversion and other musically useful processes. Alas, PictSweep's acceptable image type is restricted to PPM files, but those can be created easily with standard Linux graphics tools.
The KeyKit environment also includes a powerful object-oriented command language with support for real-time MIDI output. The following trivial example sends a Cmaj7 chord to the MIDI output device:
realtime('c e g b')
Unfortunately, I'm out of time here, so I leave the investigation of the KeyKit language to the interested reader. See the files named example*.k in the KeyKit lib directory for a good introduction to its details.
Similis sum folio de quo ludunt venti.
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
Free to Linux Journal readers.Register Now!
- Stunnel Security for Oracle
- SourceClear Open
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- SUSE LLC's SUSE Manager
- My +1 Sword of Productivity
- Managing Linux Using Puppet
- Google's SwiftShader Released
- Non-Linux FOSS: Caffeine!
- Parsing an RSS News Feed with a Bash Script
- SuperTuxKart 0.9.2 Released
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide