Glorias del Tango — New Tango Feature Film

2013 August 7
by Simba

This new project looks interesting, you can support it on kickstarter. Not sure I believe the story, but the flashbacks look promising. On the other hand, it sounds much more believeable than Assasination Tango.

“Glorias del Tango” is an ambitious and exciting feature film that will end the decade-long silence of tango on the silver screen.

I’m looking forward to it. Time to revive the tango film club?

Guide To Tango Music Stores

2013 May 23
by Simba
Last Memory of a Record Store by Telstar Logistics, on Flickr
Creative Commons Attribution-Noncommercial 2.0 Generic License  by  Telstar Logistics 

Tangohub beat me to it. Head over there for a comprehensive guide to stores for buying tango music online. It’s written from a UK perspective, but most of the stores mentioned are international.

I would mention Tangostore also (aka Zival’s), but they have been offline for a while.

Tango Tunes Website Up

2013 May 7
by Simba


The long awaited TangoTunes project website is now online and accepting purchases. I’ll start by checking out the few Troilo recordings they have available at the moment. The purchase went through very smoothly.

This is how they present themselves:

TangoTunes is an Austrian-Argentine project with the aim to preserve the music of Tango Argentino. This way, we also preserve and support a piece of Argentine culture, which was declared World Heritage several years ago.

In cooperation with TangoVia Buenos Aires we promote the project “Tango Digital Archive” with the goal to archive the recordings and documents of Tango Argentino in their entirety.

TangoTunes purchases selected collections of vinyl and shellac records from collectors in Argentina and digitizes them in a highly difficult process. Since the beginning of 2013, approximately 1.000 vinyl records and 5.000 shellac records are successively being digitized with precision and care. We offer these Tango recordings – our „tunes“ – to Tango lovers in our online store. Our product catalog is constantly expanding – it pays off to have a look more frequently!

Founded in 2013, TangoTunes is a young company located in Vienna, Austria and a branch in Buenos Aires, Argentina. We spend much time and care to restore the music of Tango Argentino as close to the original as possible. This not only requires much know-how and experience, but also great appreciation for the original and tenacious work for an ideal final result.


More Fast Transfers

2013 May 7
by Simba
Unbelievable!!! by Aleera*, on Flickr
Creative Commons Attribution-No Derivative Works 2.0 Generic License  by  Aleera* 

I have previously discussed too fast transfers from 78s. Age Akkerman has a well researched take on Di Sarli’s El ciruja which he found to be about 5% too fast on the Euro Records transfer.

Rare Clips of Petróleo, Virulazo and others

2013 March 31

Amazing how these old clips slowly surface on youtube and facebook. Here are some clips that seem to be from an old documentary, posted by Victor Barrios and Cristina Benavidez:

HT: @FerGaleraTango

El Papa Francisco

2013 March 31
by Simba

Apparently the new pope is a tango lover, and now he got his own tango. Composition and lyrics by Daniel Ursini. Courtesy of  Canciones para grabar.

Happy Easter, Papa Fracisco!

HT @milongaroom

Carlos Di Sarli Documentary

2013 March 30


According to Realidad Bonaerense, there is a new documentary about Carlos di Sarli coming out, directed by Alberto Freinquel. No information about dvd or download edition, but there will be several public viewings in Buenos Aires and in Bahía Blanca, I think. The article mentions several dramatized sequences, which makes me a bit sceptical, but I guess you have to do something if there is little historical material available.

EDIT: A bit more information here.


2013 March 29
by Simba
Oil-wheel kick drum by Paul Graham Raven, on Flickr
Creative Commons Attribution-Noncommercial-Share Alike 2.0 Generic License  by  Paul Graham Raven 

The advances in DSP and processing power since I started ripping my cds to store all my music on a computer drive are enormous.

Sometimes having an estimate of the BPM of a tango song can be useful, e.g. when searching for “slow” milongas, sorting by BPM would be useful. But tapping each song individually to store in tags — no way it’s worth the effort. I remember doing some experiments years and years ago with automatic BPM calculation, and the results were useless.

Now, on the other hand, there are open source solutions available. The one I tried got good results, better than I could achieve manually, I think. I used Sonic Annotator with a vamp plugin from Queen Mary:

The command line I used was this:

 ./sonic-annotator -d vamp:qm-vamp-plugins:qm-tempotracker:tempo -w csv --csv-stdout ../test.wav

And I did a small script to calculate for my collection. I probably should have used different parameters for vals and milonga, but I haven’t had the time to try this out (it is already a long time since I did this, trying to cope with the blog post drafts queue).

flac -d "$1" -f -o "$TMP" 2>/dev/null
BPM=$(sonic-annotator -d vamp:qm-vamp-plugins:qm-tempotracker:tempo -w csv --csv-stdout "$TMP" 2>/dev/null |head -n 1 |cut -d"," -f3)
metaflac --remove-tag=BPM "$1"
metaflac --set-tag=BPM=$BPM "$1"
rm "$TMP"

In Sonic Visualiser I could have the software play along the detected beats to see if the timing was ok. Depending on your sense of humour, this could be a funny version of what seems to be my favourite test track: Al verla pasar + kick drum


Audio Restoration from Multiple Copies

2013 March 27


I was pondering the usefulness of noise removal based on several copies of a recording, possibly from different physical copies. A Google search reveals that such a technique is already patented:

The present invention provides a method for reducing noise using a plurality of recording copies. The present invention produces a master file with lower noise than the available recording copies, and avoids the problems of losing musical content caused by prior art pop and click removers. The system comprises a recording playback unit, a computer system with a sound input capability, and a high capacity storage system such as a CD recorder. In operation, a plurality of recording copies of a single recording are played on the playback unit. These recordings are digitized by the computer and a separate recording file is formed for each copy of the recording. The recording files are then synchronized. The samples from each of the recording files are then averaged to reduce the noise components. A variety of threshold comparison techniques can be employed to eliminate samples and/or recording files that are outside of a computed range for that sample.

After doing a little more research I found the MATCH plugin for Sonic Visualiser, which sort of does what I had in mind, but I haven’t figured out how to process the aligned audio to get two aligned files:

This method is described in a 2005 paper by Simon Dixon:

Dynamic time warping finds the optimal alignment of two time series, but it is not suitable for on-line applications because it requires complete knowledge of both series before the alignment can be computed. Further, the quadratic time and space requirements are limiting factors even for off-line systems. We present a novel on-line time warping algorithm which has linear time and space costs, and performs incremental alignment of two series as one is received in real time. This algorithm is applied to the alignment of audio signals in order to follow musical performances of arbitrary length. Each frame of audio is represented by a positive spectral difference vector, emphasising note onsets. The system was tested on various test sets, including recordings of 22 pianists playing music by Chopin, where the average alignment error was 59ms (median 20ms). We demonstrate one application of the system: the analysis and visualisation of musical expression in real time.

I also found another paper by Pablo Sprechmann, Alex Bronstein, Jean-Michel Morel and Guillermo Sapiro who seem to do exactly what I had in mind. This is fresh stuff, and I found no reference to any available software implementation:

A method for removing impulse noise from audio signals by fusing multiple copies of the same recording is introduced in this paper. The proposed algorithm exploits the fact that while in general multiple copies of a given recording are available, all sharing the same master, most degradations in audio signals are record-dependent. Our method first seeks for the optimal non-rigid alignment of the signals that is robust to the presence of sparse outliers with arbitrary magnitude. Unlike previous approaches, we simultaneously find the optimal alignment of the signals and impulsive degradation. This is obtained via continuous dynamic time warping computed solving an Eikonal equation. We propose to use our approach in the derivative domain, reconstructing the signal by solving an inverse problem that resembles the Poisson image editing technique. The proposed framework is here illustrated and tested in the restoration of old gramophone recordings showing promising results; however, it can be used in other applications where different copies of the signal of interest are available and the degradations are copy-dependent.

If you happen to be in Vancouver in the end of May, you can attend their presentation at ICASSP 2013.

I’m curious as to how much difference this would make in practice compared with traditional statistical approaches. Theoretically, it would be very interesting for getting the most out of tango recordings where the masters are long gone and  would reduce less man hours for manual restoration. However, it would require extra effort as each track would have to be digitized from multiple physical copies, not to mention that you would need access to more than one physical copy of each recording. Something to think of for a project like TangoVia, that multiple copies of the same material might actually be useful.

Tango Tunes

2013 February 20
by Simba


The first results are trickling down from the TangoVia project. Tango Tunes is a Vienna based organisation, digitizing music with the help from TangoVia. They recently provided a preview of what they will offer, and I have to say I think it sounds very good. The Troilo sample in particular was very promising. The first songs available for purchase are 100 Biagi songs.  The price is EUR 100, which is expensive compared with commercial releases, but cheaper than the Japanese labels.

What it comes down to then is selection and transfer quality. The really great thing is that they will offer lossless files in high resolution (96 kHz, 24 bit) for those that have time to spend restoring music. We others can just downsample to 44.1kHz, 16 bit. Unfortunately, Biagi is not high on my prioriy when it comes to repurchasing tango music. The commercial releases are already ok quality. Troilo on the other hand, will put me first in line. Same goes for De Caro, and probably also Di Sarli. D’Arienzo will also be interesting for many DJs, I think.

I don’t know how they plan on rolling this out later, but making complete discographies available would be another thing to make them stand out. I’m crossing my fingers for complete Troilo later this year.