CBR15Passport author 
Full disclosure, I did not access the audio and video links for Twice as Many Friends / El Doble de Amigos therefore, I cannot tell you anything about that. However, I do think that I would have enjoyed this book by Brian Amador, Vanina Starkoff and Sol y Canto more if I had heard it performed.
This is not to say this book about friendship and how opening yourself up to other languages, places, and people is not good, it is terribly good. I just have this feeling that having someone read/sang to me the Spanish included would have been pleasurable and since I cannot read music (let alone sing), that “other interaction” would have worked for me. There is an afterwards to help with the Spanish phrases and pronunciations, so I was not completely lost.
The cover shows you the illustrations in all their glory! Busy and yet not overwhelming, accessible but has hidden elements and all the colors. Oh boy! The colors! They actually become their own character they are so bright. Now, sometimes a piece of the image was not exactly to my tastes (the almost abstractness of it was sometimes too much), but the art fits the tone of the story, and you will find something to enjoy about them.
This book can be adapted to multiple ages, a nice way to enhance your Spanish if you are starting out or can be used in a classroom or personal setting. While simple, this is not a simplistic book, there are layers and depth to it.