Hi frineds how r u all

After first arriving in new york, charlie parker took a job as a dishwasher at jimmy's chicken shack, where played the piano nightly. listening to his astonishing harmonic restructuring, virtuoso phrasing, and breakneck tempos every night for three months, charlie parker challenged himself to adopt these qualities into his playing, and he continued to practice tirelessly.

How did the scholars date the mosaic?

Who is depicted in the image below?