From the README:
LAME uses the MPGLIB decoding engine, from the mpg123 package, written
by: Michael Hipp (www.mpg123.de) MPGLIB is released under the GPL.Copyrights (c) 1999-2011 by The LAME Project
Copyrights (c) 1999,2000,2001 by Mark Taylor
Copyrights (c) 1998 by Michael Cheng
Copyrights (c) 1995,1996,1997 by Michael Hipp: mpglibAs well as additional copyrights as documented in the source code.
Nowadays, mpg123 is lgpl licensed. Is the license notice still valid? Can it be switched to LGPL?
Relicensing the exisitng code is not an option. There is work in progress to switch to a more recent version of libmpg123 (which would mean than any license change there would be reflected as well). There is no estimate of when this is finished.