The Flamenco guitarist is a partner to the Flamenco dancer -- two people embarking on shared but separate journeys.
Flamenco dance is not dancing steps to music; it is dancing from your heart within a rhythm structure, using Flamenco technique and being able to communicate non-verbally in a manner that a Flamenco guitarist can accompany you -- follow you not lead you. A proficient dancer knows the rhythms, a proficient guitarist knows the rhythms, and mostly that is all that is needed. The dancer knows the rhythms and leads; the guitarist knows the rhythms and follows. Period. There really is not much need for rehearsal, if any. The dancer does not follow the guitarist, the guitarist follows the dancer.
However, in many professional shows today you may see the guitarist looking off into space, deep in his/her own thoughts and not looking at the dancer. When you see that, you will know that the performance probably is highly choreographed and highly rehearsed. Everyone knows what to do and when to do it, has rehearsed it dozens of times, and it never changes. This is the difference between theatrical and improvisational Flamenco. When you see the guitarist pinned on the dancer and the dancer's feet, you know you are probably seeing improvisation, which, for my money, is the only way to really be in the heart of Flamenco.
In the photo the guitarist and percussionist (me!) are pinned on the dancer who is improvising. And, by the way, the dancer is only 10 years old and is able to lead the guitarist!
When a dancer leads the guitarist, the dancer can use whatever steps he/she may wish; but, in doing so, he/she must give very clear signals to the guitarist. Signals that tell the guitarist the dancer is going to speed up or slow down, stop or start, maybe change motifs. All of those non-verbal signals -- also improvised, must be loud and clear and in perfect compas.
One example is when a dancer starts or stops in certain rhythms, a short footwork pattern called a llamada (yah-MAH-da) is done -- a "call" to the guitarist, and it must be on a specific beat. A llamada on the wrong beat will throw everyone off.
Flamenco dancing (other than theatrical) is always improvised. "It takes two to Tango Flamenco" to make this improvisation happen -- a guitarist and a dancer, not a CD and a dancer. A CD cannot read the dancer's llamadas, interpret the dancer's feelings, or give any feeling back to the dancer; a CD cannot support the dancer. While a dancer can improvise to a CD, the loss of the human touch -- the input from a live guitarist -- always will be apparent.
In this video below you will see me and my guitarist both improvising a rhythm called Tientos. We did not rehearse any of this. I said I wanted to dance a Tientos, he said "ok" and we just started.
It is true that a dancer can dance without a guitarist, just using supporting dancers or percussionists to accompany with just palmas (rhythmic handclapping) or cajon (the box drum); I often do part of my performances with just a percussionist and it's great fun and shows excellent command of compas by both dancer and percussionist; but if a dancer wants music, it must be a live guitarist.
I tell my students that one of their most important jobs as a student is not to memorize steps or technique, but to find a Flamenco guitarist to work with right from the start. Of course the guitarist needs to understand the basics of how to accompany a dancer -- a guitarist that only plays the notes can accompany a dancer who only dances the steps, and they can do it together, but it just will be the same as if the dancer is dancing to a CD. Dancers and guitarists alike must first form a foundation of understanding of compas and then build technique.
We are fortunate in our studio to have live guitar accompaniment (at least most of the time!). One of our most important missions is to nurture Flamenco guitarists so that our dancers have guitar accompaniment and our guitarists have dancers to accompany. Students working with students, an absolute win-win for learning Flamenco.