How to Play Free Strokes on Classical Guitar
Follow-through is just as important with plucking a guitar string as it is with golf or bowling. By controlling the way your finger follows through after plucking a string, you can learn to play the free stroke, which you use for arpeggios and fast scale passages. Unlike the other fingers, the thumb virtually always plays free strokes, even when playing melodies.
To play a free stroke, pluck a string at a slightly upward angle, your finger comes to rest in the air, above the next adjacent string. (Of course, it doesn’t stay there for long, because you must return it to its normal starting position to pluck again.) That's why it's called a free stroke: your finger dangles freely in the air. The following before and after pictures, show you how to play a free stroke.
In classical guitar, you use free strokes for playing nonmelodic material, such as arpeggios (chords played one note at a time instead of all at once). Try arpeggiating the open strings (thumb on the 6th string, index finger on the 3rd, middle on the 2nd, and ring on the 1st), using all free strokes.
Try playing the free strokes in the following exercise. This is an excerpt from a Spanish piece, Malagueña, that just about every guitar player picks up at some time or other. You play the melody with the thumb while the middle finger plays free strokes on the open high-E string.
Classical guitar notation indicates the right-hand fingers by the letters p, i, m, and a, which stand for the first letters of the Spanish names for the fingers: The thumb is p (pulgar), the index is i (indice), the middle is m (media), and the ring is a (anular). You also see these notations used in fingerstyle folk guitar.