Basic technique
The creation process for an improvised verse requires strict rules to be respected in terms of rhyme, rhythm and melody, whilst at the same time developing the subject given.
As highlighted in the book "The art of improvisation: reality and keys of Basque oral improvisation", written by Joxerra Garzia, Andoni Egaña and Jon Sarasua : "It may seem paradoxical, but improvisation for the bertsolaris is very much a thought-out act. They have continuously lived out and practised situations analogous to those they may have to face, at any given moment, on the stage of their extempore art. They have learnt to work the oral and mental skills of this art form within the rules of improvised bertsolaritza (the given musical airs, rhyme, meter...) in such a way that the restrictions are not so for them, but an aid to improvise more freely. They have become used to soaking up all what may, at some time later, opportunely come in handy for the moment of improvisation".
Strategy and technique for creating
As they hear the subject which is given, the improviser’s mind springs into action firstly by thinking about the end of the verse. It’s by singing the last rhyme that the improviser will give full body and strength to the verse created. This back to front construction is the intrinsic particularity of this oral art form.
The basic technical elements to construct a bertsu are being able to sing, rhythm and rhyme, whilst at the same time developing the content.
Below are the most common forms from the point of view of rhythm and rhyme, as well as the rules about rhyme. However, the choice of rhythm cannot be dissociated form the choice of melody.