OK. We need to back up here as there are some conclusions being rendered that don't quite hold up.
For music, there is more than one copyright. There is the copyright on the original composition. There is the copyright on the modification of the original composition (for example to use modern notation, etc). There is the copyright on the recording.
Sony has a copyright on some recordings of Bach music. They may also have a copyright on modifications of the original compositions, but I don't know if they do or not. They do not hold a copyright on the original composition, because that is in the public domain.
It is difficult to record classical music without infringing copyright because the modern printed scores are all modified. You can use the original scores, but they are actually very difficult to understand and are akin to a different language. In fact, as far as I can tell this is the reasoning behind allowing a copyright on the modern scores -- they are essentially translations (and translations of creative works are allowed new copyrights).
There are some scores that are both modern and in the public domain. Kimiko Ishizaka has been doing some good work on this front with her "Open Source Bach" series (and you can even get unmixed versions of her recordings under a CC license!!!). However, initiatives on this front are few and far between (consider throwing some money her way as she is worth supporting).
If you have a score for which you have a license to record (or which is in the public domain), then you can make a recording of it. It doesn't matter one bit if it sounds like a recording of a Sony recording. However, it is quite difficult to find such scores and often performers do not know enough about copyright law when they start doing their own performances for Youtube.
For music, there is more than one copyright. There is the copyright on the original composition. There is the copyright on the modification of the original composition (for example to use modern notation, etc). There is the copyright on the recording.
Sony has a copyright on some recordings of Bach music. They may also have a copyright on modifications of the original compositions, but I don't know if they do or not. They do not hold a copyright on the original composition, because that is in the public domain.
It is difficult to record classical music without infringing copyright because the modern printed scores are all modified. You can use the original scores, but they are actually very difficult to understand and are akin to a different language. In fact, as far as I can tell this is the reasoning behind allowing a copyright on the modern scores -- they are essentially translations (and translations of creative works are allowed new copyrights).
There are some scores that are both modern and in the public domain. Kimiko Ishizaka has been doing some good work on this front with her "Open Source Bach" series (and you can even get unmixed versions of her recordings under a CC license!!!). However, initiatives on this front are few and far between (consider throwing some money her way as she is worth supporting).
If you have a score for which you have a license to record (or which is in the public domain), then you can make a recording of it. It doesn't matter one bit if it sounds like a recording of a Sony recording. However, it is quite difficult to find such scores and often performers do not know enough about copyright law when they start doing their own performances for Youtube.