Today's popular music is more complex and layered than ever before. That has a lot to do with evolving tastes and styles, and it also has a lot to do with digital multitrack recorders. Compared to the old tape recorders that were used in the past, digital technology has meant that producers can use an unprecedented number of tracks to include a wide range of instruments or even an entire classical orchestra in the recording without having to give up quality through endless remixing.
There are several rack-mounted recorders available, which are a good fit for permanent studio installations or to pack in a road case rack for a powerful travelling recording station. For something that's a bit easier to transport, you can opt for a desktop multitrack recorder. These are not only portable, they're also configured with hardware controls that make them an all-in-one digital audio workstation. If you intend to do a lot of moving the recorder from place to place, you may want to consider some of the lighter models like the TASCAM DP-03SD, Boss Micro BR-80 or Cakewalk V-Studio 100.