Following on from last week's quick post about ideas for A2 Language Investigations, here's one that might work for the AQA B spec (It's about written language, so not suitable for the A spec.) and which gives me a chance to point you towards this amazing image of rappers, names, grouped by semantic category.
So, you get rappers who have named themselves after their size (Lil Wayne, Big Pun, Big Boi, Fat Joe), money (Chamillionaire), place of origin (Cypress Hill, Sugar Hill Gang), and many many more. As well as semantic categories, the chart takes in deviant spellings, repetition and err...guys named "Rob".
Why not do your own taxonomy for a genre of your choice - Emo, Goth, Heavy Metal, or Prog Rock... or whatever you young people listen to these days. Perhaps a cross-genre comparison might be a good way to carry out an investigation.