This is the 24th column I've written for LinuxJournal.com. That's two full years of articles dealing directly with issues and news regarding the ever-expanding Linux audio software scene.

In this month's installment, I look at a few notable developments going on in that scene today. Then, I present some specific news about how I'm getting along with LilyPond these days.

I must apologize to readers who expected an article detailing with LilyPond in my recent series on music notation software. As Heather Mead pointed out in her On the Web column in last month's issue of Linux Journal, I've already reviewed the program in a previous column. However, that review covered LilyPond at version 2.2.0, almost two years ago, and its stable release is now at version 2.6.6. You can read the earlier review here and here. This time, I focus on a few of LilyPond's changes since the 2.2.0 release.

The following notes are mini-reports on the development status of some high-profile Linux audio applications. The basic Linux sound system is in good condition, with mature versions of ALSA, JACK, LADSPA, MidiShare, libsndfile and other low-to-middle level system components now available. The engines behind Linux audio applications are running nicely, thanks to various kernel tunings, and some of those applications have attained the status of professional usability. Of course, problems remain. Hardware support is still narrow compared to what's available for Win/Mac audio people. In addition, configuration difficulties still can be show-stoppers for new users.

Furthermore, GTK1.2 and Qt3 are looking dated, and some of our finest representative applications are looking dated along with them. Fortunately, the new toolkits are here, and they're looking much better, with attractions beyond the cosmetic. GTK2 and Qt4 have addressed concerns about deficiencies of the earlier versions, so programmers should enjoy better programming resources and users should enjoy greater consistency in their engagement with the program interface. Everyone wins, so it's no surprise that much recent development is concerned with a major update to the GUI.

The Ardour development team is porting the original program to GTK2. An alpha version is available for normal users, but like all alpha-stage software, the package is strictly for testing. That is, it is admittedly unstable and has been released only to identify areas demanding critical response from developers. There is currently no date planned for a beta release, but much work is going on behind the scenes. I imagine that Ardour will reach its beta release stage in a relatively short period of time. Meanwhile, you still can use the excellent Ardour 0.99, the last stable release of Ardour based on GTK1.2. A bugfix/maintenance release for 0.99 should be available by press time.

Figure 1. Ardour2 (screenshot by Paul Davis)

The Hydrogen drum machine/rhythm programmer is undergoing a facelift to bring it into the new world of Qt4. However, Hydrogen also is going through a period of redefinition. When the dust settles, we may see a very different Hydrogen, one evolved far beyond its original purpose. The developers are working on some nice design improvements to the program, including a pattern editor for pitched instruments and more powerful instrument design capabilities. These and other new features are under intense discussion on the Hydrogen developers mail list. You can check out the traffic on the list archive.

Figure 2. Hydrogen (screenshot by Artemiy Pavlov)

The first public release of Csound5 is just around the corner; in fact, it may be on-line by the time you read this article. An extraordinary amount of work has gone into this release, and its new feature list is far too lengthy to check here. It might be argued that its most outstanding new feature is the Csound API, a programmer's interface that makes it easier to write front-end programs for Csound itself. The API also makes it easier to use Csound's vast signal processing and synthesis resources within standalone external applications. Other notable improvements include a huge number of bug fixes and low-level code improvements, many new opcodes, more thorough user-level documentation, JACK support, an interface for Python and easy-to-operate installers for every supported platform. Check this column for a future report on the public release, but Csound5 is usable right now. So don't hesitate to experiment with the currently available releases.

Regular readers of this column know that I'm a big fan of Rick Taube's Common Music. For those who aren't familiar with it, Common Music is a language for generating output files and streams intended for targets such as general-purpose synthesis environments (Csound, Common Lisp Music, SuperCollider3), music notation programs (Common Music Notation, FOMUS), and real-time output via the MidiShare and PortMIDI systems. The support for FOMUS is especially interesting. Common Music now has a hook into LilyPond, giving users the powers of Common Music's generative algorithms and LilyPond's outstanding printable output. Real-time scheduling/receiving in Common Music also has seen much improvement, and the addition of the PortMIDI interface expands the number of Common Music's real-time targets. If I had to choose three computer music applications that I couldn't do without, two might change from day to day, but I'll always want Common Music.

Ardour, Hydrogen, Csound and Common Music all are multiplatform by design. Ardour and Hydrogen run on Linux and OSX, thanks to JACK, and Csound and Common Music always have been available for a wide variety of platforms, including Windows, Mac and various flavors of UNIX.

Linux audio developers and users will have the opportunity to meet and greet one another at the next Linux Audio Conference, aka LAC2006. This event returns to Karlsruhe, Germany, and will again be held at the wonderful ZKM, the Center for Art and Media Technology in Karlsruhe. The conference will take place this year April 27-30. The LAC is an important event for the Linux audio community, so make your reservations now.

LilyPond's basic usage has changed somewhat since my review of it at version 2.2.0. A default score layout now is assumed, with a soprano clef, a common-time (that is, 4/4) time signature and a C-major key signature (no sharps or flats). The screenshot in Figure 2 was produced with these two lines of LilyPond code:

  \version "2.6.3"
  {c'4 e'8 g' bes'4 a'8 g' c'4 e'8 g' bes'4 c''}

Figure 3. Simple LilyPond

The "\version" command is not mandatory, but I included it to avoid a LilyPond compiler warning.

I saved the code as ex-1.ly and processed it with only the default compiler options:

  dlphilp@localdomain:~$ lilypond ex-1.ly 
  GNU LilyPond 2.6.3
  Processing `ex-1.ly'
  Parsing...
  Interpreting music... [3]
  Preprocessing graphical objects... 
  Calculating line breaks... 
  Layout output to `ex-1.ps'...
  Converting to `ex-1.pdf'...

LilyPond's default layout output format now is PostScript, and the default conversion format is Adobe PDF. TeX/DVI still is available as an option, though. The PNG graphics format has been added as an optional LilyPond output target, and MIDI file output remains available with the "\midi" command. The "\layout" command has replaced the older "\paper", and it now is required if you want a printable format along with a MIDI file.

With those changes in place, the code from my earlier profile of LilyPond still compiles and produces the results seen in that article's screenshots. For this review I've done something different. I've been writing some classical guitar pieces, composing them with the help of a MIDI sequencer, and I've planned all along to prepare LilyPond scores for them. I used this month's column as the motivation I needed to start that project.

My pieces are saved as standard MIDI files, but I decided not to use LilyPond's midi2ly, a utility that converts a MIDI file to a LilyPond file. I wrote about midi2ly in my previous review, and I saw no reason to go over that material again. Instead, I decided to prepare the score manually, to write the code directly to a LilyPond file. It's been a long while since I worked with LilyPond, so I was essentially learning it all over again. That was fine with me; I thought it would be a good way to get intimate with the LilyPond language details.

I began by taking the time necessary to make the first measure of music look exactly as I wanted it. I copied that code and edited it to create the second measure and then copied those measures to create the third and fourth bars. Measure 5 required only slight edits to the code I created for measure 1. Measure 6 introduced new considerations, and after mastering them, I reused that code throughout the piece. As you can see in Figure 3, this piece is quite repetitive, lending itself to a fast edit/copy/paste cycle. I learned the language elements as I needed them, and it didn't take long to feel at home in the Pond.

Figure 4. Excerpt from a LilyPond Score

You can view the LilyPond source code and full PNG display for this example and others here. I should admit that although LilyPond code can be quite elegant, my code is not subtle at all. However, it is clear and it does the job. I'll keep working to be a better LilyPond user, though, and I'll update the files on my site as I improve my LilyPond chops.

By the way, I made good use of two xterms and GhostView while preparing this piece. I edited my LilyPond code in one window--with vi, naturally--compiled it in the other window and held GhostView open in its "watch" condition:

  gv --watch prelude.ly &

The display in GhostView updated immediately after each compile. Very cool.

I must compliment the LilyPond developers for their conscientious approach to documentation. LilyPond's on-line tutorials and reference materials have been created to inform clearly and succinctly and to provide the reader with immediately useful examples. The example images link to their generating code, and users are encouraged to copy and paste the example code as desired.

Figure 3 also demonstrates LilyPond's default responses to certain layout considerations. In measure 6 and all similar measures, the 8th-note stems were reversed automatically. Notice that time-signatures have been added at the end of some systems--the first four lines of music--to alert a sight-reader of a change in meter in the next system.

Notice also that where melody and accompaniment notes overlap, such as in measure 22, the collision was resolved automatically. Finally, in the last two measures of the piece (not shown here), the arpeggio signs autosized themselves to the extent of the chord.

In these and other less noticeable decisions, we see the hands of the LilyPond designers. It is important to realize that I had nothing to do with the spacing between notes, the height and direction of their stems, the shape of the arcs for slurs and ties, the bar numbers, the fonts in the title areas and many other subtle factors that affect the appearance and readability of the printed music. These factors are no mere after-thoughts. The LilyPond developers have attended to the details of music typesetting to a degree not encountered in any other notation software. And as a sight-reader, I must emphasize that the resulting score is not only good-looking, it is beautiful and perfectly readable.

Of course, I can override LilyPond's defaults at any time, for any purpose. The developers have balanced intelligent defaults with total flexibility in a way I've encountered in few other applications.

Music typesetting by copper engraving is an arcane and possibly dying art. Centuries of practice have brought that art to the perfection seen in the excellent scores published by houses such as Schirmer and Baerenreiter. Now, computer-aided typesetting has all but replaced the old way, but notation software too often has failed to reproduce the factors that went into the quality of the engraver's work. LilyPond's developers have assumed that no aspect of music notation is too small for their notice, and their attention to detail shows itself throughout the project.

LilyPond is one of the finest examples of open-source programming available, a testament to the deep research that has gone--and continues to go--into its development. Han-wen Nienhuys and Jan Nieuwenhuizen are LilyPond's core developers, but LilyPond now is the focus of a team of talented developers dedicated to producing the finest system for music notation and publication. I've met Jan and Han-wen; they are remarkable and intelligent fellows who redefine the term "enthusiastic". LilyPond has been their labor of love for many years, and their passion for excellence shows in every aspect of the program. It is equally obvious that LilyPond's community of developers and users share their dedication and passion.

That's all for this month's column. Next month I'll update my profiles of the Denemo and NoteEdit music notation editors, both of which support output formatted for LilyPond. See you then!

Ardour

Hydrogen

Csound

Common Music

LilyPond

Music Notation Software for Linux