For even the most accomplished female pianists, playing Rachmaninoff, Liszt and other virtuosic compositions can be a struggle. The problem lies not in their musical abilities, but an inherent gender bias in the way pianos are designed: 87% of women pianists (compared to only 24% of men) have hand spans smaller than 8.5 inches, the size required to play a 10-note interval, according to a peer-reviewed Australian study.