Art—so the proverb goes—flourishes on limitations. While most of Franz Joseph Haydn’s musical contemporaries, notably Mozart and Beethoven, flocked to Europe’s 18th-century cultural capital Vienna to expand their musical horizons, poor Haydn worked and composed for the princely Esterházy family on their remote rural estates. Tuesday’s (August 19) SummerFest concert offered a collage of Haydn works that demonstrated the sort of daily fare he churned out for his music-loving employers, including a pair of Baryton Trios. A curious cross between a viola da gamba and a viola d’amore, the baryton bass instrument (which became obsolete even before Haydn’s demise in 1809)…