Sevillanas is a type of folk music, sung and written in Seville (Andalusia) in Spain. Historically, they are a derivative of Castilian folk music (seguirilla). Technically, they are an evolution from Castilian seguidillas, they have a relatively limited musical pattern, but rich lyrics, based on country side life, virgins, towns, neighborhoods, pilgrimage and, of course, love themes. They are sung by a plethora of local groups, like Los Romeros de la Puebla, Los Amigos de Gines, Las Corraleras de Lebrija, Cantores de Hispalis, and Los del Río. Every year, dozens of new sevillanas discs are published.
Sevillanas can be heard in southern Spain, mainly, in fairs and festivals, including the famous Seville Fair, La Feria de Sevilla. There is an associated dance for the music: "Baile por sevillanas", consisting of four different parts. One can find schools teaching "baile por sevillanas" in nearly every town in Spain.
Generally speaking, sevillanas are very light and happy music.
Sevillana is a popular flamenco-style dance from Seville. Its rhythm is 3/4 or better 6/8.
The Sevillana did not originate in Seville. It is an old folk dance, danced by couples of all ages and sexes during celebrations (fiestas or ferias), often by whole families and 'pueblos'. Sevillanas choreography is very stable, and knowing it is very useful, since it is a fiesta dance. This is why learning flamenco usually starts with this particular dance: it is easier to reach a particular level and there are more occasions for practice and training (even for men).
Each sevillana is composed of 4 parts, with each part divided into 3 'coplas', and with each copla made up of 6 movements. It is a very vivid dance, often excluded from flamenco by "purists". Paradoxically, during spectacles and shows it is usually Sevillana dancing that ordinary people (not born in Andalusia) take for 'the real, true flamenco', as it is full of turns.