Pour info voilà la réponse du support à une question concernant les arpèges car çà avait l'air juste mais en jouant il manquait des choses pour the boxer:
Hi Alexandre,
Thanks for your interest in Riffstation. The chord viewer tool attempts to analyse the audio in order to provide the chords. The accuracy is about 85% for basic rock and pop songs but it does make mistakes from time to time. It will only find maj, min and 7th chords automatically but you can edit the chords if they are incorrect or you want to add more chords. Just right click on any chord in the orange chord strip to see the chord edit menu.
For the arpeggio in Simon and Garfunkel, unfortunately the chord viewer only detects chord harmonies and will not show arpeggios.
en espérant avoir aider