Here's an interview with Gracie and Rachel with a deeper look into their musical world. The interview is conducted by Patrick O'Heffernan on the Music Friday podcast and begins at 32:32.
[Podcast] Gracie and Rachel - Interview on Music Friday - 12-11-2015 (starts at 32:32)
Here's the direct link to the MP3
[MP3] Gracie and Rachel : Interview - 12-11-2015 (starts at 32:32)