"Hot Spot"

The Basics:

Players sit in a circle, a brave volunteer stands up and starts to sing a song. This can be any song--quality does not matter! (in fact the worse the better!) The goal is that within two lines of the song another player will step up and take over the hot spot and start singing another song. There are not preset rules or patterns about who steps up, just that everyone needs to look out for their fellow players. A more advanced version of this game involves a preset theme-- "the theme is 'color', or 'food' so all the songs must follow that theme..."

In The Classroom:

This is the improv equivalent to a trust fall activity...(except not as dangerous and not as creepy!) It is designed to give the people in the circle the opportunity to understand how it feels to step up and help someone out, or how it feels to know that there are people around you that have your back. When those feelings become contagious in a classroom, there is nothing that can't be accomplished!
During the activity encourage players to be bold! "Full Commitment!" is phrase that I often use with my improv groups. Tell them it is okay to take a risk because the group will step up if it doesn't work!
The debrief of this activity is about how it felt. If you talk about their singing--promote the most bold singer, not talent.
There are a number of improv games that require players to step up and help out a fellow player that is struggling. In fact, improv games can't happen without that sort of trust. It is one of its core values. This game is a good way to introduce that concept to students.
Setting up this atmosphere allows you to make getting up in front of the class to do curriculum based things less scary, especially if you allow for kids to help out presenters who are struggling!

Avoiding Problems:

This game works best when approached very seriously. This is a game about having people's back! When debriefing, talk about how it felt to save someone or be saved. Make it heroic.
Try to make it a fast, high energy whirlwind sort of experience. As a stage performance this game has the players pushing each other off the stage.
The danger is when no one steps up. This does not happen very often, but it could happen. The best approach to this situation is to do the same thing that you might do after any activity, without judgement or disappointment from the teacher, discuss how it felt to be out there and having no one step up to help, and what made people decide not to help... Remember, failure is a learning opportunity, and a chance to try again!
Remind them up front that this is a school and to avoid inappropriate lyrics! (Stick with the Kid Rock versions!) Remember to thank kids who stepped up and stopped inappropriate lyrics before you needed to! It's nice to see that your students have your back!

Attributions:

I first came across this game in the book, Truth in Comedy by Charna Halpern, Del Close and Kim Johnson.

I stopped using it for a while, but gave it another look after seeing Jen Olenizak give an impassioned description of it on her TEDx Talk. https://www.youtube.com/watch?v=2yNb5Dhfguw