Misc: What is the decimal equivalent of binary 1111?

Questions

what is the name of the electronic musician who won a brit award for his album "dreamland"?

who was the composer of the opera "rigoletto"?

in which three famous historical places did yanni perform at (alphabetically)?

who is the author of the bestselling "memoirs of a geisha"?

name the main character in "memoirs of a geisha". (her geisha name)?