I don't know if this has been done for old blues recordings but it certainly has for jazz. Where there's an old recording with cracks and gaps, those technical wizzards sample the sound on either side and fill in the space. A note that sounds like Louis but was never played by him. Very clever stuff but in the extreme you could end up with a whole side by Louis which wasn't. Is it justified? I'm not sure what I think of this; I suppose a little bit's OK but bits get bigger. Or would I rather listen to the crackles which weren't recorded anyway? What do other 'catters think? Dr John