Final answer:
Musicians keep their place while improvising by keeping the tune's melody in their heads and may also tap their feet or move to the rhythm to maintain tempo and structure.
Step-by-step explanation:
While improvising, musicians often keep their place by keeping the tune's melody in their heads, allowing them to stay aligned with the song's harmony and form. They may also tap their feet or move their bodies in time with the rhythm to maintain the proper tempo and feel of the piece. Disregarding the form and structure of the tune would lead to a disconnection from the original composition, which is not typically the goal of improvisation. The improvisation should enhance the existing melody and harmony, not detract from it. Some musicians may feel that staying too rigid could dampen creativity, but even in the freest forms of improvisation, a sense of place within the music's form is often retained to ensure cohesiveness and musicality.