Laser Show is one of the Achievements a player can accomplish in Audiosurf. To attain it, the player must collect matches in four colors simultaneously. This achievement can be earned with any puzzle character, but it is not possible in Casual mode since there are only three colors.
You can get four colors each on the left and right but leave the center grid clear. Each row would only contain one color, like so:
Pusher characters can then funnel the correct colors into the middle. Other characters have to wait for the blocks to be in the middle, which is a bit more risky. This strategy can fail if the right colors are not coming up to complete the matches in order. Pointman can hold a color that is coming out of order, but it is still tricky to complete.