How do I make iTunes video play slower or faster?

I want to play videos in iTunes faster (1x, 2x, double speed, etc.) or maybe slower. How do I do that?

Right click on the file in iTunes and choose "Show in Finder." Then right click the file and open in Quicktime Player. In Quicktime Player you can choose the playback speed by using the A/V Controls (Command + K or Window>A/V Controls). From there, you can select the playback speed:

Alternatively, you could use VLC or another music player.

1. Right click on the iTunes playlist and click Show in Finder
2. Right click on the content in Finder and click Open with Quicktime player.
3. While watching the video/movie press Command and then right arrow or left arrow to increase or decrease playback speed, respectively.

The Cmd+K shortcut no longer works in Lion or Mavericks.

Please see a post about increasing the playback speed in Quicktime.

The double arrow allows for integer increases in playback speed.

Quicktime Player allows you to play the audio faster, but not slower.

The chosen answer, by @daviesgeek, works for Quicktime Player 7 (Snow Leopard or earlier).

If you're on a later version (well, I only tested this on macOS Sierra and Quicktime 10.4), you can play it faster by doing:

• opt + click-on-fast-forward-button. This will increase playback by 0.1x each time.
• opt + right-arrow. This one increases from 1x to 2x to 5x.

You cannot play at a slower speed though (but you can play backwards at speeds greater than 1x).