So Ivan does have a song Mikire Zakura, but I Just Haven't Gotten Serious Yet, Interviewer, and Karakuri Pierrot are among the many songs I have for Ivan.

... Yeah, a lot of Vocaloid songs, but anything containing a struggle with who he is/how he's viewed/who he wants to be (and perhaps a Japanese flair of some fashion) will work for Ivan. In IS, he plays the shamisen. On that line of thought, Change could work too.