WEBVTT 00:00:09.360 --> 00:00:10.720 I'm Aloe Blacc. 00:00:10.720 --> 00:00:14.080 I'm a singer/songwriter and entertainer. 00:00:14.080 --> 00:00:16.840 I think computer science is really important to learn 00:00:16.840 --> 00:00:19.240 because computer science is the future. 00:00:19.240 --> 00:00:25.680 And I think it's important for people to be in control of the technology 00:00:25.680 --> 00:00:29.040 that is literally controlling their lives. 00:00:29.520 --> 00:00:34.559 To make different dance moves happen at just the right time with the music, 00:00:34.560 --> 00:00:38.080 you can use something called events. 00:00:38.080 --> 00:00:42.160 An event tells your program to listen for something to happen, 00:00:42.160 --> 00:00:44.320 and then react right away. 00:00:44.320 --> 00:00:48.800 Some examples of events are listening for a mouse click, 00:00:48.800 --> 00:00:54.360 an arrow button, or a tap on the screen. 00:00:54.360 --> 00:00:58.880 The event we're going to use now will listen for a change in the song. 00:00:58.880 --> 00:01:03.640 The change will trigger your dancer to do a new dance. 00:01:03.680 --> 00:01:10.360 Professional dancers practice their choreography by counting the beats of the song. 00:01:10.360 --> 00:01:14.960 In music, a measure refers to a certain number of beats. 00:01:14.960 --> 00:01:20.440 In most popular songs a measure is 4 beats long. 00:01:20.440 --> 00:01:24.870 To get your dancers to let loose, you'll need a green event block. 00:01:24.880 --> 00:01:30.200 This event block says after four measures. 00:01:30.200 --> 00:01:37.240 If you drag out a purple 'do forever' block, you can pick a dance for your dancer to do. 00:01:37.240 --> 00:01:40.840 Because it's under the after four measures event block, 00:01:40.840 --> 00:01:46.720 your dancer will wait for four measures of the song before starting their dance. 00:01:46.720 --> 00:01:51.100 Keep an eye on the measure counter at the top of the display area. 00:01:51.100 --> 00:01:55.520 Look and listen for the event that will trigger the dance code. 00:01:56.940 --> 00:02:00.320 And right on cue our dancer starts going!