D oes Salonen go further to say anything about music and holography? You’ve got the snippet from Salonen’s program notes about wanting to write a compact miniature that implies and acts like much more. And you’ve got the link at the bottom of the post, to the Michael Talbot Universe-as-Hologram thing. But is there a Salonen interview where he actually talks about holograms? Does he think that ‘Homunculus’ could be divided up into smaller bits and each bit would still embody all of the characters and textures of the whole [like a cut-up hologram would do]?”
— Anonymous email commenting on the previous CMT post.
I wanted to compose a piece that would be very compact in form and duration, but still contain many different characters and textures. In other words, a little piece that behaves like a big piece... I decided to call my piece ‘Homunculus’ despite the obvious weaknesses of the spermists’ thinking, as I find the idea of a perfect little man strangely moving.”T he blockquote above, which I transcribed from Esa-Pekka Salonen’s program notes, is all there is, unfortunately. I haven’t thought about it a lot (yet), but I do not think that this string quartet [its compositional structure; its acoustical properties when realized in performance] is holographic. If it is holographic, then it is a hologram of (a) ‘low resolution’ in the temporal domain and (Fourier-inverse) frequency domain and (b) represented in a nonlinear medium with ‘low quantization’ dynamic range. Just my impression.
— Esa-Pekka Salonen, program notes.
W hich draws attention to the exoticness of holograms even now, sixty-some years after holograms were discovered/invented by Dennis Gabor. The usual notion of optical holograms is that the recording medium has linear contrast formation across a very wide range—6 or more binary bits of intensity quantization or more. And the usual notion of optical holograms—oh, cut off little a corner of the hologram and illuminate it and you still get the image of the whole thing.
B ut what’s seldom expressed—or what’s seldom conveyed in popular accounts for non-physicists, anyhow—is how the hologram image from the cut-off corner differs from the image from the whole intact hologram. Yes, the little cut-off corner is itself a hologram, from which you can cut off yet another corner and once again see the ‘same’ image of the original scene. But you can’t engage in decimation of the hologram down to a minuscule, invisible ‘corner’ of film that has only one atom, say. Or digital decimation of a file that was once many megabytes in size, down till what’s left is only one binary digit—one ‘bit’, a one or a zero.
N or is a [tiny but still visible/macroscopic] holographic ‘corner’ that is 1/1000th the size of the original—one milligram of film, out of an original hologram that weighs 1 gram—capable of showing the spatial detail or contrast that the full-size original did. Over-simplified, Future-obsessed DiscoveryChannel-ified ‘lay-audience’ excuses for ‘science journalism’ has no patience for these practical facts. Instead, we get breathless, sensationalized misinformation that backhandedly suggests that Miracles happen; that Fact is Stranger than Fiction; that infinite regressions of hologram snipping do not diminish the information contained by the progressively smaller snippets. It would be so much better if the journalists and marketers and popularizers were not running the show and if instead physicists and engineers wrote or edited the copy, for longer format shows that allowed time for a bit of real-world detail...
E very part of a hologram contains the image of the whole object. You can cut off the corner of a hologram and see the entire image through it. For every viewing angle you see the image in a different perspective, as you would a real object. Each piece of a hologram contains a particular perspective of the image, but each also includes [or contains the representation of] the entire object.”S o when you cut up an optical hologram, the contrast and information corresponding to larger-scale structures does go down. Information is lost. The projected image from a tiny corner does broadly resemble the original, but its resolution is lower and other structure ‘signal’ information may now be so weak as to be overwhelmed by ‘noise’. Holograms have a ‘transfer function’ and signal-to-noise ratio (S/N), just like any other system. And those are not scale independent.
— R. Nave, Hyperphysics, Georgia State University.
A nd the same thing would happen with holographic music, notwithstanding Brian Eno’s and others’ gee-whiz comments. I do not think Salonen’s ‘Homunculus’ is holographic, in part because I do not think it has ‘extra notes’ in it. By contrast, most ‘minimalist’ and ‘ambient’ music does contain extra, dispensable notes. I do not see how Salonen’s string quartet can be shortened without the omitted elements being conspicuous for their absence. There is no way that the ‘many characters and textures’ that Salonen put in there will be preserved if we cut the piece from 12 minutes down to, say, 6 minutes or 3 minutes or 1 minute. No way.
I t would be interesting, though, to examine ‘Homunculus’ through affine transformations of tempo, which would be analogous to optically scaling holograms with changes in wavelength (the inverse of frequencies corresponding to the colors of light). You could do this in live performance—doubling the tempo, say. Or you could do it by resampling a digital recording of it—accelerating the tempo by some multiplicative factor but leaving the pitches and timbres of the strings intact. Are the expressive consequences of affine transformations of tempo similar to the consequences of reanimating an optical hologram in blue light versus red light? Do the phrases appear shorter? At the faster tempi, are the phrases’ cognitive/emotional “reach” and the strength of interactions with each other more limited in scope, compared to how they are at slower tempi?
L ikewise, are ‘polarization’ effects observed in holographic music? That is, when wavefront-aligning (polarizing) constraints are imposed on two or more voices in a piece of chamber music, then are the interference patterns manifested by the other parts also polarized? In other words, has the composer established a polarizing ‘medium’ through which all of the ‘signals’ are propagating, and does the resulting acoustic ‘image’ behave in measurable ways that are analogous to an optical ‘polarization hologram’?
I f the answer is ‘Yes’ then maybe there are other holographic features in there, too. If the answer is ‘No’, then we can add that as evidence against holographicness of ‘Homunculus’.
I s any of Ferneyhough’s writing holographic, do you think? Can we tell what is a hologram and what is not by examining the ‘text’ (score), in a way that’s analogous to how we can tell whether the image on a piece of film is holographic? How would we go about composing a piece that we intend to be a musical hologram?
- CelebrateSalonen website
- Holography page at Wikipedia
- Acoustic-Holography.com [spatial Fourier Transforms]
- Nave R. When a piece is the whole. Hyperphysics, GSU.edu
- Center for Holographic Art
- Deley D. Ambient music [with Brian Eno / Steve Roach remark about minimalism, and what holographic music is or would be if it existed].
- Brown A, Purcell K. Hologram. (Australian Music Centre, 2004.)
- Eno B. Thursday Afternoon. (AstralWerks, 1984 [2008].)
- Coulthart J. Thursday afternoon. Feuilleton blog, 05-FEB-2009. [on Eno’s views about minimalism and holography]
- Garani S. Constrained Coding and Signal Processing for Holography. VDM, 2008.
- Juhl A. Families of Conformally Covariant Differential Operators, Q-Curvature and Holography. Birkhäuser Basel, 2009.
- Kresi T. Handbook of Holographic Interferometry: Optical and Digital Methods. Wiley, 2005.
- Nikolova L, Ramanujam P. Polarization Holography. Cambridge Univ, 2009.
- Saxby G. Practical Holography. 3e. Taylor & Francis, 2003.
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