If it was part of a Music Maker bundle, it might be accessible via the Music Maker in-app store. Activation Steps
If you purchased a physical copy (on a disc), your serial number is typically found on the disc jacket or manual included in the box. sony sound forge 126 serial number link
: Search your inbox for an email from MAGIX or Sony Creative Software. For Audio Studio 12.6, the serial number is typically included in the order confirmation email. If it was part of a Music Maker
Sound Forge offers several mixing and mastering tools, including: sony sound forge 126 serial number link