F major

F major (or the key of F) is a musical major scale starting on F. Its key signature has one flat.
Its relative minor is D minor and its parallel minor is F minor.
F major is the home key of the English horn, the basset horn, the horn in F, the trumpet in F and the bass Wagner tuba. This means that if you want these instruments to sound in F major, you have to write in C major. Most of these sound a perfect fifth lower than written, except the trumpet in F which sounds a perfect fourth higher. (The basset horn also often sounds an octave and a fifth lower.)
Of the six Overtures Francesco Maria Veracini wrote for Prince Friedrich Augustus in Dresden, most are in either F major or B-flat major because the prince's orchestra had a lot of wind instruments that played best in these keys.