(Ranked according to Google hits. Bach, Madonna, and others with polyvalent names have been excluded. The names were picked and tested somewhat at random. I take no responsibility for any psychic disturbances that this list may cause.)
1. Mozart 21.6 million
2. Beatles 19.8 million
3. U2 19.1 million (includes spy plane)
4. Elvis 18 million
5. Bob Dylan 16 million
6. Britney Spears 14.9 million
7. Beethoven 14.4 million (includes movie dog)
8. Eminem 13.2 million
9. 50 Cent 12.9 million (includes markups, discounts)
10. Rolling Stones, Michael Jackson 12.2 million
11. Verdi 10.3 million
12. Mariah Carey 8.94 million
13. Sinatra 8.17 million
14. Radiohead 6.98 million
15. Donizetti 6.38 million
16. Leonard Bernstein 6.15 million
17. Beyoncé 5.05 million
18. Brahms 4.99 million
19. Björk 4.6 million
20. Vivaldi 3.89 million
21. Debussy 3.74 million
22. Death Cab for Cutie 3.55 million
23. Gershwin 3.35 million
24. Stravinsky / Strawinsky / etc. 3.14 million
25. Louis Armstrong 2.87 million
26. Sibelius 2.76 million
27. Puccini, the Sex Pistols, Toby Keith 2.68 million
28. Stockhausen 2.6 million
29. Duke Ellington 2.38 million
30. Sonic Youth 2.26 million
31. Garth Brooks 2.2 million
32. Rameau 2.11 million
33. Kurt Cobain 2.09 million
34. John Cage 2.03 million
35. Shostakovich, Schoenberg 1.99 million
36. Notorious B.I.G. 1.84 million
37. Philip Glass 1.34 million
38. The Mountain Goats 1.11 million (includes actual goats)
39. New Kids on the Block 0.87 million
40. Alex Ross + "classical music guy" 0.000078 million
P. S. A surprisingly large number of articles — 365, to be exact — mention Puccini, the Sex Pistols, AND Toby Keith.