The query appears to refer to (Opus 1) by Johann Christian Bach , a collection of six harpsichord or piano concertos published in 1763 (often cited alongside his other major early works like Opp. 7 and 13). The Story of Johann Christian Bach's Opp. 1
: A "blank 1" can refer to a flexible film blank made of Oriented Polypropylene (OPP) material used in industrial packaging. blank 1 opp 2012 skachat
: Blackmagic Design offers a Blank 1/3rd wide bay for custom console building in their Fairlight audio systems. The query appears to refer to (Opus 1)