Microeconomist Alfred Marshall explains that technology has greatly extended the power and reach of the planet's most gifted performers. He referenced a classical of opera singer Elizabeth Billington, a well-acclaimed soprano with a strong voice who could only reach a small audience and naturally did not have access to a microphone or amplifier in 1798, let alone "MTV, CDs, iTunes, and Pandora". This limited her ability to dominate the market in the way that artists to do today. Marshall wrote, "So long as the number of persons who can be reached by a human voice is strictly limited, it is not very likely that any singer will make an advance on the £10,000 said to have been earned in a season by Mrs. Billington at the beginning of the last century, nearly as great increase as that which the business leaders of the present generation have made on those of the last." Furthermore, the trends in popular music indicate that the price of the average concert ticket increased by nearly 400% from 1981 to 2012, much faster than the 150% rise in overall consumer price inflation.