Bach was not only a composer, choir director and instrumental teacher, but also a capable businessman. He rented out instruments to wealthy students of the Leipzig University and acknowledged the proper receipt of the rent payments for each of them. In the second half of 1747, the Bohemian Count Eugen Wentzel von Würben had borrowed a "keyboard" - presumably a harpsichord - from Bach and paid 32 groschen a month to the Thomaskantor for it.