The release date for Tower is a couple of days later than the release date for Pastoral, but on mamomo's site, it lists Tower as his 2nd Instrumental album and Pastoral as his 3rd, so that's what I've written in the notes.
Source:
http://www.s-mamomo.com/archives/1239
UPDATE: The source where I got the release date for Tower had it incorrect. I found an accurate source that puts the release date at April 26th, 2015. I've edited the release date field. Pastoral's release date was correct.
Source for Tower:
http://www.s-mamomo.com/archives/1542
Source for Pastoral:
http://www.s-mamomo.com/archives/1594