for more intimate relationships (see T-V distinction). Otto Jahn, in his 1856 Mozart biography, reported that Haydn and Mozart used the informal du forms in conversation, an unusual practice at the time for two people of such different ages, hence evidence for a close friendship.
For more personal connections (see T-V distinction). Otto Jahn, in his 1856 biography of Mozart, noted that Haydn and Mozart employed the casual du forms in conversation, an uncommon practice at the time for two individuals of such disparate ages, thus providing evidence of a close friendship.