The standard pronunciation is with the stress on the first syllable [man-der-tree], but a pronunciation with the stress on the second syllable is also heard [man-day-ter-ree]. The US pronunciation has the stress on the first syllable [man-der-tory].
The ‘Sun of May’ was added in 1818. The blue bands are a shade known as ‘celeste’, said to be the colour of the sky which inspired Argentine revolutionary Manuel Belgrano before battle. Effective date: 16 August 1985.