I remember going to a college party in 1979, when Grateful Dead recordings were a staple of party entertainment.

As we stepped away from the keg, we heard the opening notes of the familiar song Bertha. But this was a live version, and we were soon told that it was from a concert recorded a few months back at the Great Pyramids in Egypt. The Grateful Dead live in Egypt, and we were listening to it an apartment in Ft. Collins, Colo. Amazing, I thought! I talked to the guy who had put on the tape, and he said he had dozens of Dead show recordings—and other bands, too. Bands like Pink Floyd and Steely Dan. Thus went my first introduction to bootleg music and the tape collectors who thrived on it.

Fast-forward almost 30 years. The tape collectors of the ‘70s have long since tossed their tapes, with the serious ones digitizing these recordings onto computer hard drives, so they can be tinkered with and improved. These recordings are not the low fidelity mp3s that are commonly traded by kids today. They tend to be larger, lossless files, which the audiophile can listen to and smile at the sonic detail of the sound. The problem with these larger files is their sheer size, sometimes 75 or 100 megabytes per song, which makes it difficult to share easily due to the bandwidth constraints of many home internet connections. One concert file can easily be larger than a gigabyte, making for a lengthy download—at least at my house.

How then to download these big shows without it taking days? Enter peer-to-peer software, also called bittorrent. This technology can be the bane of any computer network security person or commercial record company. It’s an easy way to connect many users at once, using the power of multiple users to more efficiently and quickly download and upload large sets of files.

The software does require you to open up your computer to possible problems from hackers. And sometimes you walk the tightrope of downloading music that some people might consider illegal. Make no mistake; this same peer-to-peer technology is used by some people to pirate vast amounts of commercial materials like music, software, and movies. There are dozens of sites out there that do just that. But if you’re willing to take the security risks, and stick to the “legal” sites, the amount of free music out there is staggering.

To learn more about this technology and the communities that have evolved around it, the best “legal” site to head to is Etree.org. This site includes a huge database of live music, and has ongoing downloads of new and old concerts—many rare or historic. It also has information you need to learn how to use peer-to-peer software and manipulate the files you can download using those programs. There is some terminology to learn, with terms like seeds, trackers, and leechers. At first it all seemed a bit daunting, but I found learning the basics was fairly easy, and I was able to start downloading in short order.

The music available through Etree is similar to those at archive.org. It is “share friendly,” where the music is made available only after the individual artists make it known that it’s okay for you to get their music for free. Artists who do not want their music distributed for free are banned from the site, so any “no-share” music that gets posted is rapidly removed. The genres at Etree tend to be more specialized, mostly jam bands with a smattering of traditional rock, bluegrass, and jazz artists. To see what’s downloading today, go to Etree.etree.org.

You’ll be amazed when you see that concert you attended the other day, or a newly remastered recording of the Grateful Dead in Egypt 1978, are available free. And the music could be playing in your living room right now.