In "Characteristics of key signatures" Katariina Holma describes and reflects upon her experiences of  transposing her operatic singing repertoire. Do the character and colour of the sung music change when we transpose it? According to Holma's experience, it is the storyteller in particular, the role character in an opera aria, who is most affected by transposition. Holma learned during her experiment that there are several positive qualities to be gained from transposition that not only help a singer learn more about their repertoire  but also assist them in exposing stumbling blocks to their singing technique.