Bach did not restrict his acquaintance to the narrow limits of his immediate surroundings, but was in the habit of undertaking frequent journeys with the view of spreading his fame as organ virtuoso and composer. On one occasion before the end of the year 1714, he went to Cassel for the purpose of testing an organ which had been newly restored. Prince Frederick, son of the reigning duke and afterwards King of Sweden, summoned him to play in his presence and was enchanted by the unheard-of virtuosity of his pedal-playing. In the autumn of 1713, he passed some time in Halle, on his return from a professional tour, and very possibly attracted by a fine new organ, erected by Christoph Cuncius in the Church of the Holy Virgin. The post of organist at this church having been vacant for a year, it seems to have been suggested that Bach should make application for the place. The proposal must at first have been a tempting one, since the organ furnished him in Weimar was very inferior, containing in all only two manuals and twenty-four stops, while that in Halle had sixty-three sounding stops. He soon expressed his willingness to accept the appointment, and prolonged his stay sufficiently to enable him to compose the cantata required of all candidates and to conduct the performance of the same. The church elders were now very anxious to secure his services, but Bach left the place without awaiting their decision. There were many drawbacks connected with the position, and the thought of his friend and patron the duke caused him to waver. When, therefore, the formal "call" was sent to him before Christmas, in the shape of a regularly attested document, just as though the matter had already been settled between them, Bach expressed his wish to discuss the matter further before deciding. The authorities took offence at this, and, quite without reason, practically accused him of only pretending to treat with them, in order to obtain an increase of salary from the duke. The sole attraction for Bach in Halle was undoubtedly its beautiful organ. Up to this time he had been using instruments of small or medium size, and indeed, throughout his long career, an organ adequate to the genius of this greatest master in the world was never placed at his command. Meantime the bold and arrogant manner in which he was accused of evading his promise could not fail to be resented with indignation by a man like Bach. He returned a very sharp letter of protest, which plainly showed the church authorities that they had made a mistake. Realizing later their want of tact, they sought to make amends by inviting him to attend the trial performance on the new organ, and Bach accepted the invitation.