In France, there is a piano in one of the shopping centers, where everyone can play if they wish. Usually, amateurs gather at the instrument to show their skills or just children who play around. In addition, several times a week a professional jazzman shows a free piano master class and gives a short lesson to anyone who wishes.
One day a 13-year-old girl approached the instrument and began to play. It was noticeable that she played by ear and did not know the notes. Maestro offered to give her a couple of lessons, to which the girl willingly agreed. He could not even think that the child would pick up the melody so quickly and start playing.
He decided to teach her a couple of jazz chords, in particular in the ad-lib stile. He immediately realized that the girl had talent and should be used in the genre of improvisation. In popular music, ad-lib is mostly limited to the improvisation of notes and rhythmic groups (usually in the form of short melodic parts or riffs with variations) rather than tempo.
Tempo is excluded from this (with the exception of jazz music) because popular songs are mostly played at the same speed, from beginning to end. Therefore, ad-lib is mainly used when the music is climaxing, pausing and prolonging the part of the song it contains (for example, it is common in pop music to sing the highest ad-lib notes over the chorus part with an ending function).
Also, as the music comes to an end, most parts of the song have already been repeated, and so ad-lib doesn’t break its structure and dynamics. It is also possible that the music begins with an ad-lib section, but for the opposite reasons (the form and structure of the song has not yet been developed). Jazz is all about improvisation. After a couple of lessons, the girl already professionally played jazz on the piano. The professor and the audience were shocked. That’s how the talent can be found in the trading mall.