Unfortunately the license story for jFLAC is a bit complicated:
- It's a port of the C++ libFLAC which was initially licensed as LGPL but was relicensed to BSD when FLAC moved to the Xiph.Org foundation (2003)
- jFLAC started in 2004 where the code was already under BSD and used the same license in its initial commit.
- Unfortunately some original C++ source files still had the LGPL header and they were copied as-is in the Java port
- jFLAC authors then made more significant changes under the Apache license but then switched back to LGPL at some point, probably realizing they couldn't relicense it as Apache.
As a result, it's a bit unclear what license this project should use. My interpretation is that it's LGPL as it was the license headers in the C++ files that the Java port is based on. Please note that I wasn't aware of this situation until v1.5.2 of jFLAC, so version 1.5.0 and 1.5.1 advertised an Apache license as it was the one used by the SourceForge project I forked.
Please see issue #13 for more details or if you want to participate in the discussion. Thanks for @Sciss and @alexhk90 for raising this issue and looking into past commits to try to make sense of it.