<s>
MusicBrainz	B-Application
is	O
a	O
MetaBrainz	O
project	O
that	O
aims	O
to	O
create	O
a	O
collaborative	O
music	O
database	O
that	O
is	O
similar	O
to	O
the	O
freedb	O
project	O
.	O
</s>
<s>
MusicBrainz	B-Application
was	O
founded	O
in	O
response	O
to	O
the	O
restrictions	O
placed	O
on	O
the	O
Compact	O
Disc	O
Database	O
(	O
CDDB	O
)	O
,	O
a	O
database	O
for	O
software	O
applications	O
to	O
look	O
up	O
audio	O
CD	O
information	O
on	O
the	O
Internet	O
.	O
</s>
<s>
MusicBrainz	B-Application
has	O
expanded	O
its	O
goals	O
to	O
reach	O
beyond	O
a	O
CD	O
metadata	O
(	O
this	O
is	O
information	O
about	O
the	O
performers	O
,	O
artists	O
,	O
songwriters	O
,	O
etc	O
.	O
)	O
</s>
<s>
MusicBrainz	B-Application
captures	O
information	O
about	O
artists	O
,	O
their	O
recorded	O
works	O
,	O
and	O
the	O
relationships	O
between	O
them	O
.	O
</s>
<s>
Recorded	O
works	O
can	O
also	O
store	O
information	O
about	O
the	O
release	O
date	O
and	O
country	O
,	O
the	O
CD	O
ID	O
,	O
cover	O
art	O
,	O
acoustic	B-Algorithm
fingerprint	I-Algorithm
,	O
free-form	O
annotation	O
text	O
and	O
other	O
metadata	O
.	O
</s>
<s>
,	O
MusicBrainz	B-Application
contains	O
information	O
on	O
roughly	O
2.1	O
million	O
artists	O
,	O
3.5	O
million	O
releases	O
,	O
and	O
28.8	O
million	O
recordings	O
.	O
</s>
<s>
End-users	O
can	O
use	O
software	O
that	O
communicates	O
with	O
MusicBrainz	B-Application
to	O
add	O
metadata	O
tags	O
to	O
their	O
digital	O
media	O
files	O
,	O
such	O
as	O
ALAC	B-Algorithm
,	O
FLAC	B-Application
,	O
MP3	B-Application
,	O
Ogg	B-Algorithm
Vorbis	I-Algorithm
or	O
AAC	B-Application
.	O
</s>
<s>
MusicBrainz	B-Application
allows	O
contributors	O
to	O
upload	O
cover	O
art	O
images	O
of	O
releases	O
to	O
the	O
database	O
;	O
these	O
images	O
are	O
hosted	O
by	O
Cover	O
Art	O
Archive	O
(	O
CAA	O
)	O
,	O
a	O
joint	O
project	O
between	O
Internet	O
Archive	O
and	O
MusicBrainz	B-Application
started	O
in	O
2012	O
.	O
</s>
<s>
Internet	O
Archive	O
provides	O
the	O
bandwidth	O
,	O
storage	O
and	O
legal	O
protection	O
for	O
hosting	O
the	O
images	O
,	O
while	O
MusicBrainz	B-Application
stores	O
metadata	O
and	O
provides	O
public	O
access	O
through	O
the	O
Web	O
and	O
via	O
an	O
API	B-Application
for	O
third	O
parties	O
to	O
use	O
.	O
</s>
<s>
As	O
with	O
other	O
contributions	O
,	O
the	O
MusicBrainz	B-Application
community	O
is	O
in	O
charge	O
of	O
maintaining	O
and	O
reviewing	O
the	O
data	O
.	O
</s>
<s>
Until	O
May	O
16	O
,	O
2022	O
,	O
cover	O
art	O
was	O
also	O
provided	O
for	O
items	O
on	O
sale	O
at	O
Amazon.com	B-Application
and	O
some	O
other	O
online	O
resources	O
,	O
but	O
CAA	O
is	O
now	O
preferred	O
,	O
because	O
it	O
gives	O
the	O
community	O
more	O
control	O
and	O
flexibility	O
for	O
managing	O
the	O
images	O
.	O
</s>
<s>
Besides	O
collecting	O
metadata	O
about	O
music	O
,	O
MusicBrainz	B-Application
also	O
allows	O
looking	O
up	O
recordings	O
by	O
their	O
acoustic	B-Algorithm
fingerprint	I-Algorithm
.	O
</s>
<s>
A	O
separate	O
application	O
,	O
such	O
as	O
MusicBrainz	B-Language
Picard	I-Language
,	O
must	O
be	O
used	O
for	O
this	O
.	O
</s>
<s>
In	O
2000	O
,	O
MusicBrainz	B-Application
started	O
using	O
Relatable	O
's	O
patented	O
TRM	O
(	O
a	O
recursive	O
acronym	O
for	O
TRM	O
Recognizes	O
Music	O
)	O
for	O
acoustic	B-Algorithm
fingerprint	I-Algorithm
matching	O
.	O
</s>
<s>
This	O
issue	O
was	O
resolved	O
in	O
May	O
2006	O
when	O
MusicBrainz	B-Application
partnered	O
with	O
MusicIP	O
(	O
now	O
AmpliFIND	O
)	O
,	O
replacing	O
TRM	O
with	O
MusicDNS	O
.	O
</s>
<s>
The	O
Chromaprint	O
acoustic	B-Algorithm
fingerprinting	I-Algorithm
algorithm	O
,	O
the	O
basis	O
for	O
AcoustID	O
identification	O
service	O
,	O
was	O
started	O
in	O
February	O
2010	O
by	O
a	O
long-time	O
MusicBrainz	B-Application
contributor	O
Lukáš	O
Lalinský	O
.	O
</s>
<s>
While	O
AcoustID	O
and	O
Chromaprint	O
are	O
not	O
officially	O
MusicBrainz	B-Application
projects	O
,	O
they	O
are	O
closely	O
tied	O
with	O
each	O
other	O
and	O
both	O
are	O
open	O
source	O
.	O
</s>
<s>
The	O
AcoustID	O
search	O
server	O
then	O
searches	O
from	O
the	O
database	O
of	O
fingerprints	O
by	O
similarity	O
and	O
returns	O
the	O
AcoustID	O
identifier	O
along	O
with	O
MusicBrainz	B-Application
recording	O
identifiers	O
,	O
if	O
known	O
.	O
</s>
<s>
Since	O
2003	O
,	O
MusicBrainz	B-Application
's	O
core	O
data	O
(	O
artists	O
,	O
recordings	O
,	O
releases	O
,	O
and	O
so	O
on	O
)	O
are	O
in	O
the	O
public	O
domain	O
,	O
and	O
additional	O
content	O
,	O
including	O
moderation	O
data	O
(	O
essentially	O
every	O
original	O
content	O
contributed	O
by	O
users	O
and	O
its	O
elaborations	O
)	O
,	O
is	O
placed	O
under	O
the	O
Creative	O
Commons	O
CC-BY-NC-SA-2.0	O
license	O
.	O
</s>
<s>
The	O
relational	B-Application
database	I-Application
management	I-Application
system	I-Application
is	O
PostgreSQL	B-Application
.	O
</s>
<s>
The	O
server	O
software	O
is	O
covered	O
by	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
.	O
</s>
<s>
The	O
MusicBrainz	B-Application
client	O
software	B-Library
library	I-Library
,	O
libmusicbrainz	O
,	O
is	O
licensed	O
under	O
the	O
GNU	B-Application
Lesser	I-Application
General	I-Application
Public	I-Application
License	I-Application
,	O
which	O
allows	O
use	O
of	O
the	O
code	O
by	O
proprietary	O
software	O
products	O
.	O
</s>
<s>
In	O
December	O
2004	O
,	O
the	O
MusicBrainz	B-Application
project	O
was	O
turned	O
over	O
to	O
the	O
MetaBrainz	O
Foundation	O
,	O
a	O
non-profit	O
group	O
,	O
by	O
its	O
creator	O
Robert	B-Application
Kaye	I-Application
.	O
</s>
<s>
On	O
20	O
January	O
2006	O
,	O
the	O
first	O
commercial	O
venture	O
to	O
use	O
MusicBrainz	B-Application
data	O
was	O
the	O
Barcelona	O
,	O
Spain-based	O
Linkara	O
in	O
their	O
"	O
Linkara	O
Música	O
"	O
service	O
.	O
</s>
<s>
On	O
28	O
June	O
2007	O
,	O
BBC	O
announced	O
that	O
it	O
had	O
licensed	O
MusicBrainz	B-Application
's	O
live	O
data	O
feed	O
to	O
augment	O
their	O
music	O
web	O
pages	O
.	O
</s>
<s>
The	O
BBC	O
online	O
music	O
editors	O
would	O
also	O
join	O
the	O
MusicBrainz	B-Application
community	O
to	O
contribute	O
their	O
knowledge	O
to	O
the	O
database	O
.	O
</s>
<s>
On	O
28	O
July	O
2008	O
,	O
the	O
beta	O
of	O
the	O
new	O
BBC	O
Music	O
site	O
was	O
launched	O
,	O
which	O
publishes	O
a	O
page	O
for	O
each	O
MusicBrainz	B-Application
artist	O
.	O
</s>
<s>
Freedb	O
clients	O
could	O
also	O
access	O
MusicBrainz	B-Application
data	O
through	O
the	O
freedb	O
protocol	O
by	O
using	O
the	O
MusicBrainz	B-Application
to	O
FreeDB	O
gateway	O
service	O
,	O
mb2freedb	O
.	O
</s>
