Sales of portable digital music players are set to grow 57% in 2005 after growing 116% in 2004, according to iSuppli. Over the next five years, shipments of MP3 music players will expand to 132 mln units in 2009 from 36.8 mln in 2004. Sales of HDD-based players will increase to 56.2 mln units in 2009, up from 9.8 mln in 2004. By 2009, HDD players will be 43% of the total MP3 market, up from 27% in 2004.