90 collected sight singing exercises with 90 audio samples.
For beginners we recommend the following introductory books:
I.J Farkas: Practical Sight Singing, Introductory Level A
https://itunes.apple.com/book/id1031094794
I.J Farkas: Practical Sight Singing, Introductory Level B
https://itunes.apple.com/book/id1067906284