It's October—better known to Minnesota music fans as "Rocktober." More acts seem to play local music venues during this month than any other: the summer festival season is ending, and fall tours are ramping up. A lot of Minnesotans also believe touring acts try to avoid the Gopher State during our notoriously frigid winters, so they like to get in and get out before the snow falls.

Is all this truth, or just music-geek urban legends? We asked Dave Loomer, who runs MN Live, to help us take a closer look at "Rocktober." MN Live indexes a number of Twin Cities music venues, generating a Twitter feed, a Facebook page, and a Google calendar featuring local shows. (Earlier, Dave helped us discern what acts play various local music venues most often.) With data on four years of local music shows, Dave crunched some numbers and generated a couple of eye-opening visualizations.

Here's the first: watch this month's Rocktober calendar fill up as shows are announced over the course of a year. (If the visualization isn't working properly on your browser, you can also watch on YouTube.)

With respect to the second visualization, Dave Loomer writes:

To start off with, I use location data (city, state, etc.) for artists wherever possible, and use that to drive a lot of the reports. Most of the location data is pulled off of social networks like Twitter, Facebook, Bandcamp, etc. The MN Live calendar has 14,233 unique artists represented in the years 2011-2014 which I'm focusing on for the Rocktober reports. Of those, 9,639 (67.7%) have location data at at least a state/province level (or country level outside the US and Canada), and 8,789 (61.7%) have location data pinpointed down to the city. The location reporting assumes that this ~65% is representative of the larger sample of all 14,233 artists who are on the calendar over those four years in terms of location relative to Minneapolis.

Some random facts...

Of the 3,832 artists who played the Twin Cities in 2014 for which I have location data, 1927 (or 50.3%)were from outside of Minnesota.

880 of those 1,927 touring artists from 2014 had not played the Twin Cities before.

In an average year, the busiest 30-day stretch of touring bands coming to town is Sept. 24-Oct. 23, with 295 touring acts. The lightest stretch is Dec. 17-Jan. 15 (65 touring acts on average).

A 30-day stretch comprises 8.2% of the possible dates in a year. During the 30-day stretch of Sept. 24-Oct. 23, 15.7% of a year's touring bands play in 8.2% of the available dates in a year.

In an average year, touring artists total up 2,363,728 total miles from Minneapolis in terms of distance from their hometown to here.

In terms of miles from Minneapolis, in an average year the period from Sept. 24-Oct. 23 is the 30-day stretch during which acts come from the furthest distance from Minneapolis (median 1043 miles). Dec. 17-Jan. 15 is the shortest-distance month (median 862 miles). Sept. 10-Oct. 9 is the biggest stretch in terms of TOTAL miles (121,879 miles) whereas Dec. 17-Jan. 15 is the lightest (21,656 total miles).

532 of 1,359 touring artists who played in 2009 have not returned to Minneapolis again. (note that we shouldn't read much into the fact that I've tracked 1,359 touring artists in 2009 vs. 1,927 in 2014; the calendar is probably just more complete today than it was then).

Here's a "heat map" showing the places touring artists come from over the course of a year. (Here's the map on YouTube, if it's not appearing properly for you.)