For MusicBrainz, our beta site is now all HTTPS, web service and all. The main, non-beta musicbrainz.org will be going HTTPS-only except for what’s under /ws/ (ie., the web service) to allow taggers and other programs not currently using HTTPS some transition time. We do not currently have an ETA for when we will make the final jump to HTTPS-only on the MusicBrainz web service, as that partly depends on feedback from our web service users, which leads me to:
If you’re currently using the MusicBrainz web service, please try and switch your program to using beta.musicbrainz.org and see whether your program breaks or not and let us know the status of it. We are aware that some Python versions and MusicBrainz libraries do not support our setup, so while your program may fail now, it might simply be because of dependencies of your program not being updated yet and you might not need to do anything specifically on your end – however, some programs/libraries might need some updates, so the more people test and report back, the better we’ll be able to judge when we can go all-HTTPS-only on musicbrainz.org.
For AcousticBrainz, we now have a shiny new Let’s Encrypt certificate on https://acousticbrainz.org thanks to our systems administrator Zas! As a result, we are going to start redirecting all HTTP traffic to HTTPS on the AcousticBrainz website, including API queries.
In order to give everyone time to verify that their scripts correctly recognise and validate our Let’s Encrypt certificate, we are going to delay the redirect until July 1, 2016. On this date, any HTTP query will automatically be redirected to HTTPS. We will also enable HSTS, so that compliant browsers will redirect to HTTPS on the client-side.
If you have any questions about either the MusicBrainz or the AcousticBrainz transition, please ask.
It’s been over a year since we last posted about AcousticBrainz, but a lot of work has been going on in the background. This post will give an overview about some of the things that we’ve achieved in the last year.
Our last blog post was neatly titled “What do 650,000 audio files look like, anyway?” Back then, we thought that this was a lot of submissions. Little did we know… I’m glad to report that we now have over 3.5 million submissions, of which almost 2 million are for unique MBIDs. This is a great contribution and we’d like to thank everyone who submitted data to us.
Dataset and model building
MusicBrainz coder Gentlecat returned to participate in Google Summer of Code last year and developed a new tool to let us create datasets and create new computational models. We’re really excited about how this can allow community members to help us increase the quality of the semantic information we provide in AcousticBrainz. We will make another blog post soon explaining how it works.
We presented an academic overview of AcousticBrainz (PDF) at the 16th International Society for Music Information Retrieval (ISMIR) conference in Malaga, Spain. The feedback from the academic community was very encouraging. Many people were interested in the data and wanted to know what they could do with it. We hope that there will be some new projects announced using the data at this year’s conference.
Integration with other data sources
MusicBrainz and AcousticBrainz don’t exist in a vacuum. One important thing that we need to make sure we do is interact with other researchers and products in the same field. To that end, we started AcousticBrainz Labs, a showcase of some of the experiments that we’re working on in AcousticBrainz. The first thing we have published is a mapping between AcousticBrainz and the Million Song Dataset, that we hope people will use to compare these two datasets.
Database upgrades and Data format changes
We’ve just upgraded to PostgreSQL 9.5 (from 9.3), which allows us to use the new jsonb datatype introduced in PostgreSQL 9.4. This change lets us store feature data more efficiently. We also made some changes to the database schema to let us start creating new data from datasets and computation models.
One result of this is that we are creating a new complete data dump, and stopping the old incremental dumps. We are also taking the opportunity to automate this incremental dump process, which is something that a number of people have asked for.
Another change is that the format of the high level JSON data is changing. This is to better reflect some of the complexities that exist in hosting such a large and varied dataset.
Contribute to AcousticBrainz development
We’re always interested in help from other people to contribute data, code, and ideas to AcousticBrainz. Once again, MetaBrainz is participating in Google’s Summer of Code, and AcousticBrainz is a possible project to work on. If you’re not a student you’re still welcome to work with us.
Hot on the heels of our release of the first 650,000 feature files as part of the first release of AcousticBrainz, we are presenting some initial findings based on this dataset.
We thank Emilia Gómez (@emiliagogu), an Associate Professor and Senior Researcher at the Music Technology Group at Universitat Pompeu Fabra for doing this analysis and sharing her results with us. All of these results are based on data automatically computed by our Essentia audio analysis system. Nothing was decided by people. Isn’t that cool?
The MTG recently started the AcousticBrainz http://acousticbrainz.org/ project, in collaboration with MusicBrainz. Data collection started on September 10th, 2014, and since then a total of 656,471 tracks (488,658 unique ones) have been described with essentia. I have been working for a while with audio descriptors and I followed the porting some of my algorithms to essentia, especially chroma features and key estimation. For that reason, I was curious to get a look this data. I present here some basic statistics. I computed them with the SPSS statistical software.
WHICH KIND OF MUSICAL GENRES DO WE HAVE IN THE COLLECTION?
In order to characterize this dataset, I first thought about genre. In essentia, there are four different genre models: trained on the data by Tzanetakis (2001), another one compiled at the MTG (Rosamerica), Dortmund and a database of Electronic music. Far from providing information on the kind of musical genres, these models seem to be contradictory! For example, in the Tzanetakis dataset “jazz” seems to be the most estimated genre, while the proportion of jazz excerpts is very small in the other models.
So in conclusion, we have a lot of jazz (according to the Tzanetakis dataset), electronic music (according to the Dortmund dataset), ambient (according to electronic dataset) and an equal distribution of all generes Rosamerica dataset (which does not include a category for electronic music)….Not very clarifying then! This is definitely something that we will be looking at in more depth.
WHAT ABOUT MOOD THEN?
For Mood characterization, 5 different binary models were trained and computed on the dataset. We observe that there is a larger proportion of non-acoustic music, non-aggressive, and electronic. It is nice to see that most of the music is not happy and not sad! From this and previous study, I would then conclude that there is a tendency in the AcousticBrazinz dataset for electronic music.
The amount of electronic music (compare with the acoustic graph above)
If we check for genre vs mood interactions, there are some interesting findings. We find that Classical is the most acoustic genre and rock is the least acoustic genre (due to its inclusion of electronic instruments):
HOW IS KEY ESTIMATION WORKING?
From a global statistical analysis, we observe that major and minor modes are both represented, and that the most frequent key is F minor / Ab Major or F# minor / A Major. This seems a little strange; A major and E major are very frequent keys in rock music. Maybe there are some issues with this data that need to be looked at.
IS THERE A LINK BETWEEN FEATURES AND GENRE?
I wanted to do some plots on acoustic features vs genres. For example, we observe a small loudness level for classical (cla) music and jazz (jaz), and a high one for dance (dan), hip hop (hip), pop, and rock (roc).
Finally, it is nice to see the relation between equal-tempered deviation and musical genre. This descriptor measures the deviation of spectral peaks with respect to equal-tempered tuning. It’s a very low-level feature but it seems to be related to genre. It is lower for classical music than for other musical genres.
We also observe that for electronic music, equal tempered deviation is higher than for non-electronic music/acoustic music. What does this mean? In simple terms, it seems that electronic music tends to ignore the rules of what it means to be “in tune” more than what we might term “more traditional” music.
IS THERE A LINK BETWEEN FEATURES AND YEAR?
I was curious to check for historical evolution in some acoustic features. Here are some nice plots on the evolution of number of pieces per year, and some of the most relevant acoustic features. We first observe that most of the pieces belong to the period from 1990’s to nowadays. This may be an artifact of the people who have submitted data to AcousticBrainz, and also of the data that we find in MusicBrainz. We hope that this distribution will spread out as we get more and more tracks.
There does not seem to be a large change of acoustic features as year changes. This is definitely something to look into further to see if any of the changes are statistically significant.
We have many more ideas of ways to look at this data, and hope that it will show us some interesting things that we may not have guessed from just listening to it. If you would like to see any other statistics, please let us know! You can download the whole dataset to perform your own analysis at http://acousticbrainz.org/download
What is AcousticBrainz?
The AcousticBrainz project aims to crowd source acoustic information for all of the music in the world and make it available to the public. The goal of AcousticBrainz is to provide music technology researchers and open source hackers with a massive database of information about music.
AcousticBrainz uses a state of the art research project called Essentia (http://essentia.upf.edu/), developed over the last 10 years at the Music Technology Group.
Data generated from processing audio files with Essentia is collected by the AcousticBrainz project and made available to the public under the CC0 license (public domain). In 6 weeks since its inception, AcousticBrainz contributors have already submitted data for 650,000 audio tracks using pre-release software.
Today we are releasing client programs to submit data to the AcousticBrainz server and our first public release containing audio features for over 650,000 audio files.
What data does it have?
AcousticBrainz contains information called audio features. This acoustic information describes the acoustic characteristics of music and includes low-level spectral information such as tempo, and additional high level descriptors for genres, moods, keys, scales and much more. These features are explained in more detail at http://acousticbrainz.org/sample-data
What can I do with it?
We hope that this database will spur the development of new music technology research and allow music hackers to create new and interesting recommendation and music discovery engines. Here are some ideas of things we would like to see:
Improving the state of the art in genre recognition
Analytics on the musical structure of popular music
This is one of the largest datasets of this kind available for research, and the only one of this size that we know of which contains both freely available data as well as the reference source code used to compute the data.
How can I contribute? If you are a music researcher, you can help us by contributing to the essentia project. Go to the essentia homepage to see how you can do this. If you do something cool with the data let us know. We’d like to start a “made with AcousticBrainz” page where we will showcase interesting projects.
If you have any audio files, we would love for you to contribute audio features to our project. You can do this by downloading our submission clients from http://acousticbrainz.org/download. We provide clients for Windows, Mac, and Linux.