Posts Tagged ‘WIN’

Add MusicNet data to COPAC with ‘Composed’ bookmarklet

03 Oct

Here’s a great example of how the MusicNet data can be used to enhance existing sites. The ‘Composed’ bookmarklet decorates an existing COPAC composer record with all the extra information that MusicNet contains about that person.

Head on over to this blog post for more details. Incidentally this was created as an entry to the UK Discovery competition we blogged about earlier in the year.

So, who’s going to turn this into a GreaseMonkey script so that the bookmarklet isn’t need?


UK Discovery Developer Competition features the MusicNet dataset

11 Jul

The MusicNet dataset has been included as part of the UK Discovery global developer competition. The rules of the competition are simple, build an app/tool that makes use of at least one of the 10 featured datasets.

UK Discovery is working with libraries, archives and museums to open up data about their resources for free re-use and aggregation. DevCSIis working with developers in the education sector, many of who will have innovative ideas about how to exploit this open data in new applications.

This Developer Competition runs throughout July 2011. It starts on Monday 4 July – Independence Day, a good day for liberating data – and closes on Monday 1 August. It’s open to anyone anywhere in the world.

For more information about the competition see Prizes are available for the best entrants, competition ends Monday 1 August 2011.


Final Product Post: MusicNet & The Alignment Tool

29 Jun

This is a final report and roundup of the MusicNet project. We’ll mainly be discussing the primary outputs of the project but will also cover an overview of the project as a whole.

We have two primary prototypal outputs/products from the project, they are:

  1. The Alignment Tool
  2. The MusicNet Codex

We’ll discuss each of these in turn and address what they are, who they are for and how you can use them in your own projects.

Read the rest of this entry »


Tweets from Music Linked Data Workshop (#MLDW)

24 May

Here are the archived tweets from the Music Linked Data Workshop we held at JISC London earlier this month. Slides from the event can be found here.

Read the rest of this entry »


MusicNet URI scheme and Linked Data hosting

19 Jan

MusicNet’s key contribution is the minting of authoritative URIs for musical composers, that link to records for those composers in different scholarly and commercial catalogues and collections. MusicNet claims authority because the alignment across the sources has been performed by scholars in musicology. The alignment tool and the progress to date has been detailed previously. In this post I will overview our methodology for publishing our work, in terms of the decisions made in choosing our URI scheme and how we model the information using RDF in the exposed Linked Data. I will then describe the architecture for generating the linked data, which has been designed to be easily deployed and maintained, so that it can be hosted centrally in perpetuity by a typical higher education computer science department.

URI Scheme

The URI scheme is designed to expose minimal structural information, for example, the URI for Franz Schubert is currently (see below for a volatility note):

It is comprised of the domain name (, an abstract type (person), an ID taken from the musicSpace hash of the composer (7ca5e11353f11c7d625d9aabb27a6174) and a fragment to differentiate the document from the person (#id).

We have chosen a hash rather than a human-readable label because we want to avoid people using the URI because they think that it refers to a composer when it might refer to a different composer. This is important in this domain because there are a number of composers with the same or similar names. Part of the alignment process has musicologists make this distinction. By forcing people to resolve the URI and check that it is the person they are referring to, we aim to avoid incorrect references being made. In addition it gives us the freedom to alter the canonical label for a composer after we have minted the URI, so that we don’t have a label-based URI with a different label in its metadata.

Domain Name

We intend for the domain name to change soon from one which isn’t explicitly tied to mSpace – this is in place right now for convenience to us. In particular our requirements are a domain that will not cost us anything to re-register in future, will remain in our control (i.e. not get domain parked if someone forgets to renew), and will not dissuade people from using it for any partisan or political reasons. The closest we might reasonably get is, although this is still unconfirmed at this point in time, and we may have to instead use or, which are not preferred, since they might give the impression that the data is a Southampton-centric view of the information, which it is not. For a more in depth discussion of a proposed solutions see our previous posts ( proposal & revisited)

Ontological Constructs

In addition to the scheme for the URI, we also had to determine the best way to expose the data in terms of the ontological constructs (specifically the class types and predicates) used in the published RDF. We are fortunate that an excellent set of linked data in the musical composer domain already exists, in the form of the BBC /music linked data. For example, the BBC /music site exposes Franz Schubert with the URI:

The BBC’s data uses the Music Ontology heavily, as well as other ontologies such as SKOS, Open Vocab and FOAF. Since we are publishing similar data, it makes sense for us to use the same terms and predicates as they do where possible, which is what we have done.

We are still in the process of finalising how we will model the different labels of composers. In the figure below we offer two possible methods, the first is to create a URI for each composer for every catalogue that they are listed in, publishing the label from that catalogue under the new catalogue-based URI, and use owl:sameAs to link it to our canonical MusicNet one. The second method is to “flatten” all labels as simple skos:altLabel links, although this method loses provenance. Currently we do both, and we’ve not finalised whether this is necessary or useful.


RDF model for MusicNet alternative labels

RDF model for MusicNet alternative labels



Content Negotiation & Best Practice

Similarly, we also follow the BBC /music model of using HTTP 303 content negotiation to serve machine-readable RDF and human-readable HTML from the same URI. Specifically, the model we’ve borrowed is to append “.rdf” when forwarding to the RDF view of the data, and to append “.html” when forwarding to the human readable view of the data. This is now implemented, and you can try this out yourself with the above URIs, which you can turn into the following:

There are several other offerings from the MusicNet site, some of which have been detailed before. First, the MusicNet Codex, which is the human search engine for MusicNet. In addition we have also created a (draft!) VoiD document that describes the MusicNet data set, available here:

The perceptive among you will notice that the VoiD document links to an RDF dump of all of the individual linked data files, available here (14MB at time of writing):

Simple Deployment & Hosting

As noted above, our requirements state that our deployment must be as simple as possible to maintain by typical higher education computer science department web admins. In our bid we stated that we will work with the Southampton ECS Web Team to tweak our solution. As such, in order to keep our deployment simple, we have adopted an architecture where all RDF (including the individual Linked Data files for each composer) are generated once and hosted statically. The content negotiation method (mentioned above) makes serving static RDF files simple and easy to understand by web admins that might not know much about the Semantic Web. Similarly, the VoiD document and RDF dump get generated at the same time. The content negotiation is handled by a simple PHP script and some Apache URL rewriting.

Benefits of Linked Data

One of the benefits of using Linked Data is that we can easily integrate metadata from different sources. One of the ways in which we use this is using the aforementioned BBC /music linked data. Specifically, we enrich our Linked Data offering through the use of MusicBrainz. One of the sources of metadata that we have aligned is musicbrainz, based on a data dump we were given by the LinkedBrainz project team. The BBC also have aligned their data to Musicbrainz, and thus we have been able to automatically cross-reference the composers at the BBC with the composers in MusicNet. Thus, we can link directly to the BBC, which offers a number of benefits. Firstly, it means that users can access BBC content, such as recently radio and television recordings that feature those composers (see the Franz Schubert link above, for examples), but also that we can harvest some of the BBC’s outward links in order to enrich our own Linked Data offering. Specifically, we have harvested links that the BBC make to pages on IMDB, DBPedia, Wikipedia, among others, which we now re-publish.

The data flow from the raw data sources to linked data serving is illustrated in the figure below.

MusicNet Architecture Data Flow Diagram

MusicNet Data Flow Diagram

Future Work

The following tasks remain in this area of the project:

  1. Acquire control of a long-term domain name (preferably, see above).
  2. Discuss our RDF model with experts in Linked Data, Ontological Modelling and Provenance.
  3. Determine if we will offer a SPARQL endpoint in future. If we decide not to ourselves (because it might not be sustainable once our hosting is passed over to the department), it might be desirable to put the data on the Data Incubator SPARQL host.

This post documents Work Package 3 from the MusicNet project deliverables. MusicNet is funded through the JISCEXPO programme.


Performance & Usability Improvements

09 Dec

Lately we’ve been working hard to improve the workflow of our Alignment Tool. Based on the real user experience of the musicologist using the tool daily, we were able to implement some simple performance and UX (User Experience) updates that have had a dramatic effect on efficiency.

The improvements we’ve made and the effect they’ve had on the workflow are outlined below – although some of these may seem simple, it’s only in hindsight and after real-world user testing that the need for such tweaks becomes apparent.

Starting Point

When we released Beta 1 of our tool, we ran some benchmarks to get a sense of how quickly the alignment task could be achieved. Initially we found that the rate at which you could create verified matches was: 135/hr.

Performance Improvements, Phase 1

Alphabetically auto-sort newly created groups

In Beta 1, newly created groups were pushed to the bottom of the groups list so as to reduce the need to re-sort and re-render a potentially large list – a procedure that typically doesn’t perform well in a Javascript environment.  However, this is problematic from a UX perspective: after creating a new group, the alphabetical sorting of the grouped item column is corrupted, which makes comparing its contents to the alphabetically sorted ungrouped column more time consuming.

Happily, recent improvements to Javascript engines and the uptake of ECMAScript 5 functions, such as Array.sort(callback), allow the browser itself to perform the re-ordering rather than us coding it in a Javascript routine. By altering the behaviour of the alignment tool so that groups added to the grouped item column are now listed in their correct alphabetical position, we were able to improve the user experience and remove the difficulty in comparing the contents of the ungrouped and grouped item columns. In testing the change we were unable to make the browser stall or freeze during the re-sort/re-render and did not notice a reduction in interface speed or responsiveness.

Scroll to newly created groups

In Beta 1 this action was the default as we knew that the new group would be at the bottom of the list. In changing to the re-sorting model we needed to work out where the newly created group resided in the list and then scroll the list to make sure the element was visible in the lists viewport.

As it turns out this was quite a simple process, the server returns the ID of the newly created group which allows us to find the element on the DOM after its been sorted. We can then work out how much to scroll the list based on the newly created group elements offsetTop property.

We also added a small Javascript ‘blink’ animation to draw the users attention to the newly created group.

Highlight List Items

When examining the associated metadata in the right hand metadata view pane for a group that has been suggested by the system, sometimes items’ metadata might be ordered differently to how items were listed in the column. Using the Beta 1 code this posed a problem if the entries labels were all identical, as it meant there was no way to identify which metadata belonged to which list item.

To solve this we added a hover effect in the metadata view pane which highlighted the associated list item, allowing for much quicker and accurate removal of single items.

Phase 1 Improvements led to a new match rate of 169/hr (25% improvement on Beta 1)

Performance Improvements, Phase 2

Fix Diacritics

A lot of the tooling we used to generate the datafiles we required as input to Alignment Tool didn’t seem to handle diacritics as well as expected. Specifically all the composers we had imported from the Grove database seemed to have escape characters placed in front of any diacritic. The diacritic remained in tact but there were just extra characters in the string.

We programmatically removed these characters to aid readability during the alignment process.

Create a Merge function

One feature we were missing in Beta 1 that we anticipated we might need was the ability to merge two or more groups into one. The most common use cases where this was required are (i) where the system generates two different groups for the same composer based on two re-occuring variations in name usage, or (ii) where the user creates a new group for ungrouped items, before realising that a suitable group for these items already existed.

This function has now been added and can be found in the Alignment Tool SVN repository on Google Code.

Phase 2 Improvements led to a new rate of 279/hr (106% improvement on Beta 1)