Uses ffmpeg to convert all that annoying .FLAC files to MP3 files keeping all the Artist's information in them.

$ find . -name "*.flac" -exec ffmpeg -i {} -ab 160k -map_metadata 0 -id3v2_version 3 {}.mp3 \;
ffmpeg version 2.8.4 Copyright (c) 2000-2015 the FFmpeg developers
  built with Apple LLVM version 7.0.2 (clang-700.1.81)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/2.8.4 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-opencl --enable-libx264 --enable-libmp3lame --enable-libvo-aacenc --enable-libxvid --enable-vda
  libavutil      54. 31.100 / 54. 31.100
  libavcodec     56. 60.100 / 56. 60.100
  libavformat    56. 40.101 / 56. 40.101
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 40.101 /  5. 40.101
  libavresample   2.  1.  0 /  2.  1.  0
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  2.101 /  1.  2.101
  libpostproc    53.  3.100 / 53.  3.100
Input #0, flac, from './01 The Grateful Dead - Uncle John's Band.flac':
  Metadata:
    TITLE           : Uncle John's Band
    ARTIST          : The Grateful Dead
    ALBUM           : Workingman's Dead (2003 reissue)
    GENRE           : Rock
    COMPOSER        : Bill Kreutzmann;Bob Weir;Jerry Garcia;Phil Lesh;Ron "Pigpen" McKernan
    ENSEMBLE        : The Grateful Dead
    track           : 1
    DATE            : 2001
    ALBUM ARTIST    : The Grateful Dead
  Duration: 00:04:45.33, start: 0.000000, bitrate: 854 kb/s
    Stream #0:0: Audio: flac, 44100 Hz, stereo, s16
Output #0, mp3, to './01 The Grateful Dead - Uncle John's Band.flac.mp3':
  Metadata:
    TIT2            : Uncle John's Band
    TPE1            : The Grateful Dead
    TALB            : Workingman's Dead (2003 reissue)
    TCON            : Rock
    TCOM            : Bill Kreutzmann;Bob Weir;Jerry Garcia;Phil Lesh;Ron "Pigpen" McKernan
    ENSEMBLE        : The Grateful Dead
    TRCK            : 1
    TYER            : 2001
    ALBUM ARTIST    : The Grateful Dead
    TSSE            : Lavf56.40.101
    Stream #0:0: Audio: mp3 (libmp3lame), 44100 Hz, stereo, s16p, 160 kb/s
    Metadata:
      encoder         : Lavc56.60.100 libmp3lame
Stream mapping:
  Stream #0:0 -> #0:0 (flac (native) -> mp3 (libmp3lame))
Press [q] to stop, [?] for help
size=    5574kB time=00:04:45.33 bitrate= 160.0kbits/s    
video:0kB audio:5573kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.015331%