In 1773 the 17 year old Mozart had likely seen the printed music for string quartets by Haydn who by that time was a master of string quartet writing. Mozart then gave himself a challenge to live up to the Haydn model and composed six string quartets (Mozart’s “Viennese Quartets” Nos 8-13, known to show some of Haydn’s influence). Ten years later Mozart likely first met Haydn and the two became fast friends sharing mutual high esteem. At this time Mozart, now more experienced, wrote six more Quartets which he sent to Haydn with a letter of dedication to him. At the premiere of these new quartets Haydn told young Mozart’s father Leopold, “before God and as an honest man I tell you that your son is the greatest composer known to me either in person or by name.” The only Quartet of these six “Haydn Quartets” in a minor key, No. 15 in d-minor (K. 421), is today’s Midday Masterpiece at 2:00 pm.