Unless you have a booking agent, it is very difficult to book venues for a tour. If you are a new band it can be intimidating to play your first show. So the house party was formed. House parties are not just jam sessions, although jam sessions could occur because of a house party. House parties are low key shows that one or more bands can play at. Usually the owner of the house hosting the party invites their friends and people who may know the people in the band.
For a new band this allows you to play your first show for a very supportive crowd. If the show goes terribly you are in front of your friends who will forgive you and not judge, at least I would hope not. It is a less stressful environment to test the waters and to learn from mistakes such as the video below from a 2011 house party.
For touring bands, without a booking agent, sometimes it is just near impossible to get decent venues to book an out of town band. If you are lucky you will break even and be able to cover gas money from one city to the next. These house parties usually offer support for those touring bands and if you are lucky people might like your music and buy some 'merch' or even better donate money to your cause.
For the guests attending these can be really fun parties. You get to socialize with friends and usually drinking is involved. If you are lucky you'll get to enjoy some great entertainment as well, so next time you are invited to a house party I highly encourage you to go. Go in without any preconceived notions, and you may just have a blast.
Photos and Video: courtesy of Anna Blanton