 As of January 6, 2009, all four big music studios ( Warner Bros., Sony BMG, Universal  , and EMI ) have signed up to remove the DRM from their tracks, at no extra cost.
<fluency>  As of January 6, 2009, all four big music studios ( Warner Bros., Sony BMG, Universal  , and EMI ) have signed up to remove the DRM from their tracks, at no extra cost.
 As of January 6, 2009, all four big music studios Warner Bros., Sony BMG, Universal , and EMI ) have signed up to remove the DRM from their tracks, at no extra cost.