The oldest and most well-known form of Galician music is the alalas, a form of chanting that has been associated with Galician nationalism. They share characteristics with Celtic nations as well as Castilian, German, Arab and other Mediterranean-area peoples. Their origin is shrouded in mystery, with some scholars asserting Gregorian chants as a major souce, while others point to Greek or Phoenician rowing songs called alelohuías.
Alalas are arhythmic and based on a single, short theme that repeats the melody, separated by instrumental bagpipes or a cappella vocals. Melodies are based on a continuous drone and are almost always diatonic. Over time, alalas have adapted to include choral polyphony which has added harmony and rhythms (most typically in 2/4 or 3/4 time) to the tradition. The melody is formed by repeating all of its notes. A unique characteristic of alalas is that the first cadence is also the last, and they end in an enlarged coda that fades into a sustained and undefined sound.
Instrumentation is usually nothing more than bagpipes (usually in Bb tonality) and various percussion instruments. The hurdy-gurdy was, until recently, also played.
In the 20th century, a Galician roots revival occurred, led by performers like Faustino Santalices and Perfeuto Feijoo.