An announcement of this event was published by Prager Morgenpost 24/12/1863, noting: ‘Musical trial [Musikprobe]. Sunday 27th December 1863 takes place in the Hall on Žofín Island the Musical Trial to the Socety Ball [Gesellschafts-Ball] arranged for 2nd February for the benefit of the Institute for the Education and Well-being of poor Blind Children [Privaterziehungs- und Heilinstituts für arme blinde Kinder]. The commencement [presumably meaning of the trial] is 4 o’clock.’ The ‘Musikprobe’ would not have simply constituted a rehearsal of the musical items to be performed at the ball, but would have been an advance presentation of the works being performed.

The Tagesanzeiger daily almanac of Prague social and musical events published by Prager Morgenpost 27/12/1863 announced: ‘4pm. Musical trial for the Society Ball [Gesellschaftsballe] for the Benefit of the Institute for the Education and Well-being of poor blind Children on the Žofín Island.’