The Divertimento K. 138 in F major was written in 1772, a date which carries various social, political, and musicological connotations – but more fundamentally that Wolfgang Amadè* Mozart was only 15 years old at the time.
Then, he was a celebrated child prodigy and pride of Salzburg under the wing of his father Leopold, a wing he would find difficult to fly from later in life. That was also the year that Count Hieronymus Colloredo was elected Prince-Archbishop, with whom he would eventually develop a stormy working relationship.
The divertimenti written in this period reflect the innocence of his youth. The genre, prior to more formal categorization from 1780, was generally “diverting” music, in the sense of light, possibly outdoor music or even as background music for some social event.
The Grove Online entry references H.C. Koch’s definition of music that should “please the ear rather than express different shades of emotion.” It is ironic then that today’s ‘proper’ performances of the work in concert halls may less reflect the context of the era than its use during wedding gigs.
In any setting, however, the beauty of the composition remains clear more than two hundred years later. In the style of the operatic composer he was destined to be, the singing melodic lines of the first violin take the lead through the first two movements, only giving some equal ground to the other string parts in the closing rondo movement.
Mozart – Divertimento in F major, K.138