The elmcity project’s newest hub is called Madison Jazz. The curator, Bob Kerwin, will be aggregating jazz-related events in Madison, Wisconsin. Bob thought about creating a Where hub, which merges events from Eventful, Upcoming, and Eventbrite with a curated list of iCalendar feeds. That model works well for hyperlocal websites looking to do general event coverage, like the Falls Church Times and Berkeleyside. But Bob didn’t want to cast that kind of wide net. He just wanted to enumerate jazz-related iCalendar feeds.

So he created a What hub — that is, a topical rather than a geographic hub. It has a geographic aspect, of course, because it serves the jazz scene in Madison. But in this case the topical aspect is dominant. So to create the hub, Bob spun up the delicious account MadisonJazz. And in its metadata bookmark he wrote what=JazzInMadisonWI instead of where=Madison,WI.

If you want to try something like this, for any kind of local or regional or global topic, the first thing you’ll probably want to do — as Bob did — is set up your own iCalendar feed where you record events not otherwise published in a machine-readable way. You can use Google Calendar, or Live Calendar, or Outlook, or Apple iCal, or any other application that publishes an iCalendar feed.

If you are very dedicated, you can enter invidual future events on that calendar. But it’s hard, for me anyway, to do that kind of data entry for single events that will just scroll off the event horizon in a few weeks or months. So for my own hub I use this special kind of curatorial calendar mainly for recurring events. As I use it, the effort invested in data entry pays recurring dividends and builds critical mass for the calendar.

Next, you’ll want to look for existing iCalendar feeds to bookmark. Most often, these are served up by Google Calendar. Other sources include Drupal-based websites, and an assortment of other content management systems. Sadly there’s no easy way to search for these. You have to visit websites relevant to the domain you’re curating, look for the event sections on websites, and then look for iCalendar feeds as alternatives to the standard web views. These are few and far between. Teaching event sponsors how and why to produce such feeds is a central goal of the elmcity project.

When a site does offer a Google Calendar feed, it will often be presented as seen here on the Surrounded By Reality blog. The link to its calendar of events points to this Google Calendar. Its URL looks like this:

1. google.com/calendar/embed?src=surroundedbyreality@gmail.com

That’s not the address of the iCalendar feed, though. It is, instead, a variant that looks like this:

2. google.com/calendar/ical/surroundedbyreality@gmail.com/public/basic.ics

To turn URL #1 into URL #2, just transfer the email address into an URL like #2. Alternatively, click the Google icon on the HTML version to add the calendar to the Google Calendar app, then open its settings, right-click the green ICAL button, and capture the URL of the iCalendar feed that way.

Note that even though a What hub will not automatically aggregate events from Eventful or Upcoming, these services can sometimes provide iCalendar feeds that you’ll want to include. For example, Upcoming lists the Cafe Montmartre as a wine bar and jazz cafe. If there were future events listed there, Bob could add the iCalendar feed for that venue to his list of MadisonJazz bookmarks.

Likewise for Eventful. One of the Google Calendars that Bob Kerwin has collected is for Restaurant Magnus. It is also a Eventful venue that provides an iCalendar feed for its upcoming schedule. If Restaurant Magnus weren’t already publishing its own feed, the Eventful feed would be an alternate source Bob could collect.

For curators of musical events, MySpace is another possible source of iCalendar feeds. For example, the band dot to dot management plays all around the midwest, but has a couple of upcoming shows in Madison. I haven’t been able to persuade anybody at MySpace to export iCalendar feeds for the zillions of musical calendars on its site. But although the elmcity service doesn’t want to be in the business of scraping web pages, it does make exceptions to that rule, and MySpace is one of them. So Bob could bookmark that band’s MySpace web page, filter the results to include only shows in Madison, and bookmark the resulting iCalendar feed.

This should all be much more obvious than it is. Anyone publishing event info online should expect that any publishing tool used for the purpose will export an iCalendar feed. Anyone looking for event info should expect to find it in an iCalendar feed. Anyone wishing to curate events should expect to find lots of feeds that can be combined in many ways for many purposes.

Maybe, as more apps and services support OData, and as more people become generally familiar with the idea of publishing, subscribing to, and mashing up feeds of data … maybe then the model I’m promoting here will resonate more widely. A syndicated network of calendar feeds is just a special case of something much more general: a syndicated network of data feeds. That’s a model lots of people need to know and apply.