For the past few months I have been trying the Naxos Music Library, a service which, for €25/month allows you to listen to as much streaming classical music (and jazz) as you can take. Now that might seem a bit steep, but consider this gives you access to the whole Naxos catalogue (which, for non-US residents, has a large number of out-of-copyright classic recordings), and the catalogues of other great labels like BIS, Chandos, Hungaroton, Music & Arts, Ondine and more …

Quality is fine (256kb/s if you've the bandwidth), and I've really enjoyed listening to, for example:

• Nathan Milstein playing a jaw-dropping Bach D Minor Partita at the Library of Congress in 1953 on Bridge.
• Ronald Brautigam's ongoing cycle of Beethoven sonatas on the fortepiano, on BIS.
• Semyon Bychkov's revelatory (really) recording of Mahler 3 with the WDR Chorus and Symphony Orchestra, Cologne on Avie (so good I bought the CDs).
  
• Practically everything recorded by Yan Pascal Tortelier with the Ulster Orchestra for Chandos.
  

But…

The technologies available to stream the music are Flash, Silverlight or "Windows Media Player", and all of them have a huge problem: they cause pauses between tracks. On my fast (20Mb/s) connection it's for just a couple of seconds, but the effect can be ruinous. So today (it being Easter time) I am listening to the famous 1951 Knappertsbusch/Bayreuth recording of Parsifal — at the end of the weightiest, most yearning Vorspiel one can imagine, as the woodwind sing out into the Bayreuth gloom and the strings disappear into the stratosphere we are suddenly plunged into inky digital silence before the first scene begins. The spell is broken and part of my soul is chipped away.

This is a serious problem and really rules this service out of contention for music lovers who want to listen to opera or through-composed pieces where gapless replay is essential. If nothing else, it would be a reasonable stop-gap (hah!) to rip entire discs into single streamable entities as an alternative way of getting the bits.