Aisha starts with 500 songs + 500 songs = <<500+500=1000>>1000 songs added to her mp3 player in the first two weeks.
After that Aisha adds twice that amount to her mp3 player, 1000 x 2 = <<1000*2=2000>>2000 songs added.
She now has 1000 + 2000 = <<1000+2000=3000>>3000 songs on her mp3 player.
However, she decides she wants to remove 50 of them, 3000 - 50 = <<3000-50=2950>>2950 songs on her mp3 player.
#### 2,950