A theme is usually the subject of a work of music. A motive is a fragmentary idea. In music motives are used as a kernel from which a larger work is built. Think of a scale as the pool of notes that a composer uses to write his or her piece. Most cultures employ a scale as the basis for their music, and there are many varieties of scales to choose from.
Scales are one of the ways in which cultures differ quite strongly from one another.
Japanese scales have 5 note, while some Arabian scales use 17 notes. Here are some examples of scales from different cultures- you'll probably recognize the Western ones. Here People often ask how a composer chooses what scale to use. The answer is that different scales have different sounds and often different associations in the minds of both the composer and the listener. If this sounds intimidating to you, or you think that you could never distinguish between scales, you've got a pleasant surprise coming, as I'll show you in a moment, because we all have a certain sensitivity toward scales.