# NXT Musical Instrument

Name of Activity

NXT Musical Instrument

Author

Jay Clark

Keywords

Mary Had A Little Lamb, simple song, NXT, switches, sensors, task, instrument, wiring, math blocks, programming, loops, MINDSTORMS, Music Engineering, numerical frequency, audible, pitch, 2 Hours Total

Subject

NXTs

4, 5, 6, 7, 8, 9+

Time

2 Hours Total

Brief Description

Students will play “Mary Had A Little Lamb” and other simple songs on their NXT using switches and touch sensors. When students complete that task, they will make an instrument using other sensors, requiring wiring and math blocks in their programs.

Lesson Objectives:

Learn about loops, switches, and math blocks

Introduce Musical Instrument Engineering

Understand the relationship between numerical frequency and audible pitch

Materials Needed:

NXT Kit

Computer with MINDSTORMS NXT software

Necessary Background

Mary had a little lamb is a simple song consisting of just three notes. The notes and corresponding lyrics are below:

E D C D E E E

D D D E E E

lit-tle lamb, lit-tle lamb

E D C D E E E

E D D E D C

whose fleece was white as snow

All musical notes have a corresponding frequency. Concert A (or middle A) is 440 Hz. In order to play mary had a little lamb using a light or distance sensor, you must know the frequencies of the three notes you’re using:

C – 262

D – 294

E – 330

Vocabulary:

frequency – the rate at which a vibration occurs. Determines the pitch of a note.

Procedure

Introduction Introduce switches to the students. A switch is a program structure that makes decisions based on external criteria, such as a sensor value. Introduce the lesson. Show the students the notes of Mary had a little lamb. Ask them how many touch sensors they would need to play it. Guide them to realize that they could use 2, and there are 4 opportunities for notes to play with two touch sensors: Left pressed, right pressed, both pressed, none pressed. Guide them through brainstorming how the program should look. Usually it’s hard for them to see that the second switch is required. ActivityHave the students program their robots to be able to play mary had a little lamb using switch blocks and sound blocks. When they finish, have them use another sensor and wiring and math blocks in their program to create another musical instrument. Or allow them to use switches with another sensor to set up ranges for each note.

Extensions:

Play a different song!

Use touch sensors in conjunction with another sensor to set the octave.

Reference 1

http://sites.tufts.edu/stompactivitydatabase/files/formidable/g.png

You must be