Without a teacher
Start immediately with Bob’s ten built-in songs. No sign-in, class code, or download is needed.
Movement meets music
Drop a beat.
Build a dance.
Choose teacher-approved music. Bob builds a routine and coaches your class one eight-count at a time while the original video plays.
🔎 How do Bob’s moves and camera work?Choose how to begin
Dance now or join your class
Choose a song →
With a teacher code
Enter the six-character student code to open only the songs your teacher approved for your class.
Without a teacher
Choose a song
Ten ready-to-use choices. The video picture stays covered while the music plays.
Or learn a known routine
Line dances
Bob teaches the established steps and follows the song timeline.
Macarena
Hand-timed official 16-count sequence
Cupid Shuffle
Right · left · kicks · walk and turn
Cha-Cha Slide
The real called moves—listen and respond
The Sid Shuffle
The documented 32-count Ice Age dance
The song players show words instead of dancers. The Sid Shuffle’s official video is covered by a music-only screen because a dependable lyric video is not available. Nothing is downloaded or copied.
♪
♪ CLASS MUSIC
Open your class playlist
Enter your student class code once. Bob will remember it on this computer and load your teacher’s latest approved songs next time.
Teachers
🔒 TEACHER CONTROLS
Teacher chooses the music options
Students can use a class playlist after their teacher approves songs. Teachers may unlock YouTube links and audio uploads here.
Teacher sign in or manage classes →Paste a YouTube link
Bob plays the original video—nothing is downloaded or copied.
or use audio only
Use videos that may be embedded and that you have permission to use in class.
Want audio only? Upload an audio file you are allowed to use. YouTube links must play through YouTube’s visible official player.
Bob’s learning lab
How does Bob see a dance?
Explore how dance steps become Bob poses, how a computer can spot body landmarks, and where similar camera technology appears in real life.
People designed Bob’s move library
Each move has a name, an easy coaching cue, and four key poses. Bob shows those poses across eight counts. The remix button chooses a new combination from the selected difficulty.
- Name it“Grapevine”
- Describe itSide, behind, side, tap
- Pose itChoose four body shapes
- Count itMatch the shapes to 1–8
Bob fact: The YouTube video supplies the music. Bob does not copy a dancer from that video or invent a move by watching it.
The camera turns a picture into points
When you choose Turn on camera, your browser asks permission. MoveNet looks for keypoints such as shoulders, wrists, hips, knees, and ankles. Bob compares their positions with his current pose and gives a practice score.
🔒 Your video stays with you.It is processed in the browser. Bob does not record it, upload it, recognize your face, or learn your name. Stopping early still gives feedback from the usable poses already seen.
The people behind the movement
Where do Bob’s moves come from?
Dancers and teachers built Bob’s library from movement patterns used in many styles. A move can travel, change, and appear in more than one dance tradition—so these are connections, not ownership labels.
Step Touch · March · Side Sway · Clap & Reach
Stepping, shifting weight, marching, reaching, and clapping are basic ways people organize movement with a beat. You may see them in warm-ups, folk and social dances, jazz, hip-hop, musical theatre, and classroom choreography. They do not have one single inventor.
Also connects to: Freeze Pose · Turn & Point · Level SwitchBody Roll · Bounce Back · Slides · Freezes
Hip-hop culture grew through Black and Latino youth communities in New York City during the 1970s. Breaking developed around musical “breaks.” Related funk styles—including locking, popping, and boogaloo—grew in Black communities on the West Coast. Bob’s simple rolls, bounces, slides, and freezes borrow broad ideas used in today’s street and studio choreography; they are not complete versions of those traditions.
Listen for: a strong beat, accents, groove, improvisation, and personal style.Kick-Ball-Change · Syncopated Slide · Slide & Clap
Kick-ball-change is common in jazz, tap, cheer, and musical-theatre combinations. American tap developed over centuries through exchanges among West African and British Isles step-dance traditions, then grew alongside jazz music. “Syncopated” means placing an accent where the listener may not expect it.
Try it: say “kick-ball-change” as three quick weight changes.Pas de Bourrée · Pivot Turn · Level Switch
Pas de bourrée is a small traveling step used in ballet and later in jazz and other stage styles. Ballet developed from Renaissance court entertainment in Italy and France before becoming a professional theatre form. Modern and contemporary choreographers expanded the movement choices, often using the floor, off-balance shapes, and dramatic changes of level.
Translation clue: pas is French for “step.”Grapevine · Pivot Turn · Step Touch
The grapevine travels sideways by crossing one foot behind or in front. Variations appear in social, folk, line, country-western, jazz, and aerobic dance. Its path through dance history is difficult to trace to one beginning—one reason careful researchers say where a move is used instead of declaring a single inventor.
Pattern clue: side · cross · side · tap.Explore the history with a grown-up:Smithsonian: Hip-Hop Dance ↗Library of Congress: Tap Dance in America ↗Pittsburgh Ballet Theatre: Ballet History ↗
Where else do cameras understand movement?
- 🎮Motion-controlled games
A camera can turn a jump, reach, or swing into game controls.
- ⚽Sports practice
Athletes can study body position, balance, and repeated motion.
- 🧑⚕️Physical therapy
With an adult professional, movement tools can help practice safe exercises.
- 🚗Driver-assistance cameras
Cars may use cameras to notice lanes, signs, people, and other vehicles—not dance poses.
Questions for curious dancers
How is Bob’s camera like a motion-controlled video game?
Both turn camera pictures into useful points or shapes, then compare the movement with something the program expects.
Why does Bob need to see your hands and feet?
Missing landmarks make the body shape incomplete. Stepping back helps the camera see the whole pose.
Would a self-driving car look for wrists and ankles?
Usually no. It looks for road objects such as lanes, signs, cars, cyclists, and pedestrians. Different jobs need different training examples.
What could make a camera guess incorrectly?
Low light, a blocked body part, moving too quickly, standing too close, or confusing backgrounds can make landmarks harder to find.
What rule would you make for using cameras fairly?
Ideas: ask permission, explain what is saved, collect only what is needed, and always provide a no-camera choice.
5 · TRY MACHINE LEARNING
See how a computer finds a pose
Google’s PoseNet camera demo draws dots at body landmarks and connects them like a digital stick figure. It does not know that you are dancing—it estimates where parts such as your shoulders, elbows, wrists, hips, knees, and ankles may be in each camera picture.
- Try one person at a time with the whole body in view.
- Test the conditions: move closer or farther away, change the light, or partly hide one arm. What changes?
- Look for uncertainty: the dots may jump or disappear when the computer cannot see a body part clearly.
Before you open it: ask your teacher or grown-up. The separate Google demo will request camera permission. Follow your school’s camera rules, and close its tab when you are finished.
Experiment 1: Find the body dotsUse Google’s PoseNet camera
- Open the experiment and ask a grown-up before allowing the camera.
- Stand back until the camera can see you from head to feet.
- Make a pose. Look for dots on your shoulders, elbows, wrists, hips, knees, and ankles.
- Be a scientist. Try brighter light, a darker room, standing sideways, or hiding one arm. Which dots stay? Which dots disappear?
Experiment 2: Teach two posesUse Google’s Teachable Machine
What is a class? A class is just a named group. You might make one class called Star Pose and another called Crouch Pose. The computer learns which group a new pose belongs in.
- Open the pose trainer. Choose camera and allow it with a grown-up’s permission.
- Name Class 1 “Star Pose.” Hold a star shape and press or hold the record button to collect lots of pictures called examples. Turn a little or move your arms so the examples are not all exactly the same.
- Name Class 2 “Crouch Pose.” Record lots of crouch examples too. Try to collect about the same number for both classes.
- Choose Train Model. Wait while the machine studies your examples.
- Test it. Try each pose in the preview box. Watch the bars or percentages. Does Star Pose get the biggest score when you make a star?
- Challenge it. Make a pose halfway between the two. Did the machine feel less sure? Why?
No coding, download, or student login is needed. Use a desktop browser, follow your school’s camera rules, and close the experiment tab when you finish.
Learn a step
Practice with a dance teacher
These earlier step-by-step videos are back. Use them when you want to slow down, learn the pattern, and practice one move at a time.
The videos open on YouTube and are not embedded here. Ask your teacher or grown-up before leaving Bob’s Dance Lab.
Interactive challenge
Move Detective
Bob pauses before a short performance clip to tell you when to focus. After the move, the video pauses again and you choose what you saw.
Ready to investigate?Bob will pause before the mystery move.
BOB’S CLUE
Modern dance mystery
Watch how the dancer changes height and shape.
The activity uses YouTube’s official player. If a video owner or school network blocks playback, use the performance link below instead.
Watch, spot, wonder
Spot Bob’s moves in a performance
These are professional performances—not lessons. Watch the whole dance, or choose a short section and see how many familiar moves you can spot.
The videos open on YouTube and are not embedded here. Ask your teacher or grown-up before leaving Bob’s Dance Lab.
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MODERN DANCERevelations by Alvin AileyProfessional company performance · AILEYWatch for: big reaches · levels · turns · freeze shapes
▶CONTEMPORARY BALLETWithin the Golden Hour21st-century choreography · The Royal BalletWatch for: turns · balance · flowing shapes · level changes
▶HIP-HOP & STREET DANCE2 vs. 2 World Final BattleProfessional competition performance · Red Bull Dance Your StyleWatch for: bounce · slides · body rolls · freezes · turns