## Maths in Music

3/24/2010

We are currently investigating maths in music.

The task over 2 lessons is to look at patterns (rules) in lyrics and music and present these patterns via a digital poster. This activity helps reinforce previous knowledge on Percentages and Algebra, applied to a very real context.

The class is using Taylor Swift's song, The Best Days. They are all working with their buddies.

Finding patterns in lyrics

Students look at visual patterns using Wordle or WordItOut to find the most common words (Mode). They count the occurences of words in the lyrics and write out algebraic rules in expression form and also in words, e.g.

(k / w) * 100% as the percentage of the word 'know' in the lyrics

In fact, this is how Word Clouds (like Wordle and WordItOut) work, i.e. by correlating the frequency of occurrence and the font size on the resulting graphic.

Finding patterns in music

Year 8s are currently learning how to play the guitar. Part of this task is to look at the song's chords and create a Frequency Distribution Table and Chart in Excel spreadsheets. This reinforces a previous topic on Percentage Composition as well as a review of some Data concepts.

Students look at a visual representation of music in Audacity to see peaks and troughs in the volume as well as when repeated segments occur.

Students can then play with the Tempo and its effects in beats per minute and duration of a 15-second music segment. Audacity shows the percentages of change visually as well as in numbers.

Music students can opt to look at patterns using music sheets for the same song. It is hoped that students see that knowledge of fractions (and percentages) are very much in use here.

Maths is in Music

Students are engaged and are using a variety of ICT tools to help them see the maths in music. They get to see how information can be presented in a variety of ways.

Posters will be showcased on this web so keep visiting.

## Current Topic - Algebra

3/14/2010

We've just finished Percentages and have started Algebra.

We are refining our algebraic techniques which we've started learning in year 7. These include the four operations (add, subtract, multiply, divide) as well as basic Index Laws and expansion of expressions, possibly even factorising...maybe.

Some very basic things to remember are:
• pronumerals (the letters) represent numerical values - numbers in disguise; also known as variables (opposite of constant), because the values they represent can change
• numbers before letters (coefficient then pronumeral) when writing terms, e.g. 2y
• numbers before letters when multiplying and dividing pronumerals, e.g. 3b x 4c = 3 x 4 and b x c = 12bc
• no need to write 1, e.g. write b, instead of 1b
• invisible operation means to multiply, e.g. 8m or 9(n+ 1) both mean multiply
• like terms (matching pronumerals) apply to addition and subtraction, e.g. 4a + 5a, and 6mn - 2mn
• x and x-squared are not like terms
• b + b is not the same as b x b, b + b = 2b but b x b = b^2; ^ means raised to the power of
• rule means formula or equation or number sentence, i.e. expect to see the = sign, e.g. A = bh, t = 2m + 1. Rules can have variables and/or constants.
• algebraic expressions do not have the = sign, e.g. 3a + 5
• in Algebra, use what you learned about operating with whole numbers, directed numbers, fractions, decimals and percentages as well as order of operations

It's hard to believe that we've actually covered all of the above already.