Possible Clues:

• G major analog
• Key of Chopin's Piano Concerto No. 1
• Key of Brahms's Fourth
• Key of Dvorák's "New World Symphony"
• It shares the same keys as a G major scale
• Key of Dvorák's Symphony No. 9
• Mendelssohn's Violin Concerto is in it
• Chopin's Waltz in ___
• Relative key of G major
• Key of a Bach 'Bourrée'