The MOOC Music and mathematics presents a series of lessons that focus on the rhythmical structures found in Karnatic music. These structures which are explained and performed with a mathematical approach in terms of ratios, establish a core for executing polyrhythms precisely as well as rhythmical accuracy in any way. Throughout the series we will get an insight on how we can approach rhythm with a mathematical way, defining rhythmical patterns as numbers, thus combining them and resulting into various rhythmical layers that co-exist. Besides the polyrhythmic approach we will also get into linear structural tools to create rhythmical lines as well as tools on how to develop them.