What is a Jam Session?

Readers of this site will see that we have written a few blogs that cover jam sessions and famous musicians. We thought it might make a bit of sense to go into detail about what a jam session actually is. Hopefully, this will be useful to the first-time visitors as well, who can then understand more about the topics covered here.

Jam Session Definition

So, if we scour the internet, we can gather a vast amount of information that relates to jam sessions.

Here is our definition:

  • A jam session is a reasonably informal musical event where the musicians perform without any form of rehearsal

Jam sessions can often take place with amateurs who all join together to produce one sound. However, there are also occasions when jammers are professional, sometimes recording their jam for production purposes. Jamming is thought to date back to around the early 1920s, a period when both black and white music makers would congregate to play the kind of music they couldn’t normally play.

Influences on Jamming


Jazz was certainly one of the earliest of influencers on jam sessions, with the New York scene during the 2nd world war being particularly noted. At the time, there was one big jam session that was really getting recognized; it came in the form of the regular after-hours sessions at Harlem, NY City.

Afro Cuban

Once jazz had gained a stronghold in jam sessions, it wasn’t much longer before the afro-Cuban mix came along and started to shake things up a little. These improvised jam sessions saw the semblance of extended versions which proved to be popular with a great many people, with the likes of Cachao and Julio Gutierrez seen as the pioneers.


Perhaps it comes as no surprise that rock music has had the biggest influence in jamming. Onstage jamming, often referred to as free impro, has become syndemic with rock-stars of all ages. There is just something about throwing down some chords on the guitar, with the bass stepping in to carry things on, that crowds go wild for.

Without doubt, the biggest jammers of their own era were:

  • Jimi Hendrix
  • Led Zeppelin
  • Santana
  • Pink Floyd

There has even been what’s referred to as “jam bands”. The Grateful Dead were amongst the very first to fully adopt this genre into their music; however, to be fair, Cream played their part by building in long impros on the tracks they recorded.


In most cases, Bluegrass jams occur in low-key areas, such as campgrounds of festivals, music stores, parking lots and restaurants. Open jams, like the ones mentioned above, will normally require players to have a modicum of proficiency about them. There are also numerous private jams where professional musicians turn their hand to the production of something quite unique. Hopefully this blog has given you a little more of an insight into the background and history of the jam.

Be sure to stay tuned for our next post!