That's the way the improvisatory business is managed for visitors.
"The Gypsies" by Charles G. Leland
This accounts for the digressive, irregular, improvisatory manner of his prose.
"The Memoirs of Count Carlo Gozzi; Volume the first" by Count Carlo Gozzi
Improvisatorial addition of ornaments, especially popular in playing the Baroque music, does not change the overall melody.
Music in Terms of Science