physician turned the tide; he changed the treatment, and by the end of the month she was recovering. Then Wolfgang fell ill, and it was mid-December before he was on his feet again. Both children were able to appear at the Oude Doelen on 22 January 1766, in a concert which may have included the first public performance of one of Wolfgang's London symphonies, K. 19, and possibly of a new symphony in B flat major K. 22, composed in the Netherlands. Following this concert they spent time in Amsterdam before returning to The Hague early in March. The main reason for their return was the forthcoming public celebrations of the Prince of Orange's coming of age. Wolfgang had composed a quodlibet (song medley) for small orchestra and harpsichord, entitled Gallimathias musicum, K. 32, which was played at a special concert to honour the Prince on 11 March. This was one of several pieces composed for the occasion; Wolfgang also wrote arias for the Princess using words from Metastasio's libretto Artaserse (including Conservati fedele, K. 23), and keyboard variations on a Dutch song Laat ons juichen, Batavieren! K. 24. He wrote a set of keyboard and violin sonatas for the Princess, as he had earlier for the French princess and for the Queen of Great Britain. Another symphony, K. 45a, commonly known as "Old Lambach" and once thought to have been written several years later, was also written in The Hague, possibly for the Prince's coming-of-age concert. The family left The Hague at the end of March, moving first to Haarlem, where the organist of St Bavo's Church invited Wolfgang to play on the church's organ, one of the largest in the country. From there they traveled east and south, giving concerts along the way at Amsterdam and Utrecht at 21 April, before leaving the Netherlands and traveling through Brussels and Valenciennes, to arrive in Paris on 10 May. Homeward journey (April–November 1766) The family remained in Paris for two months. No concerts were given by them in this period although, according to Grimm, there were performances of Wolfgang's symphonies. Grimm was effusive about the development of both children; Nannerl, he wrote, "had the finest and most brilliant execution on the harpsichord", and: "no-one but her brother can rob her of supremacy". Of Wolfgang he quoted a Prince of Brunswick as saying that many Kapellmeisters at the peak of their