If you've ever tried to listen to Pink Floyd albums in MP3 format, you'll know what we're talking about: Albums with "continuous track" material.

Some albums have songs which run together. For instance, on Pink Floyd's Dark Side of the Moon, the song Money blends smoothly into the next song, Us and Them. If you perform a standard rip of this album, and play it back in a standard MP3 player, there will be a slight "blip" in between the two songs. This small space of silence sounds something like a skip in the recording.

As of version 2.0 of the Rio Car player software, gapless playback is fully supported. The player will play two tracks precisely adjacent to each other without inserting any space between them at all.

However, there's a big "but..." attached to this.

MP3 files themselves are not inherently gapless. In fact, most MP3 encoders will insert artificial silence into the beginning and end of each MP3 file. It's part of the encoding process, and it's not a bug. The authors of the LAME and BladeEnc encoders are working on ways around this, but these require careful configuration in order to work their magic, and it is reported that they are not yet 100 percent perfect in their results.

So just because the player can play files gaplessly doesn't mean that they will sound right when played back. The files themselves probably have bits of silence at the beginning and end of each file. The player will faithfully play back this silence, since it's part of the MP3 file.