<s>
Synthesia	B-Application
is	O
a	O
piano	O
keyboard	B-Device
trainer	O
for	O
Microsoft	B-Application
Windows	I-Application
,	O
iOS	B-Application
,	O
macOS	B-Operating_System
,	O
and	O
Android	B-Application
which	O
allows	O
users	O
to	O
play	O
a	O
MIDI	O
keyboard	B-Device
or	O
use	O
a	O
computer	B-Device
keyboard	I-Device
in	O
time	O
to	O
a	O
MIDI	O
file	O
by	O
following	O
on-screen	O
directions	O
,	O
much	O
in	O
the	O
style	O
of	O
Keyboard	B-Application
Mania	I-Application
or	O
Guitar	B-Application
Hero	I-Application
.	O
</s>
<s>
Additionally	O
,	O
Synthesia	B-Application
can	O
be	O
paired	O
with	O
MIDI	O
keyboards	B-Device
that	O
have	O
illuminated	O
keys	O
,	O
or	O
with	O
virtual	O
player	O
piano	O
on	O
screen	O
,	O
which	O
some	O
people	O
believe	O
makes	O
learning	O
piano	O
easier	O
for	O
beginners	O
.	O
</s>
<s>
It	O
was	O
originally	O
named	O
Piano	B-Application
Hero	I-Application
,	O
due	O
to	O
the	O
similarity	O
of	O
gameplay	O
with	O
Guitar	B-Application
Hero	I-Application
;	O
this	O
was	O
until	O
Activision	O
(	O
the	O
owners	O
of	O
the	O
rights	O
to	O
Guitar	B-Application
Hero	I-Application
)	O
sent	O
a	O
cease	O
and	O
desist	O
to	O
the	O
program	O
's	O
creator	O
,	O
Nicholas	O
Piegdon	O
.	O
</s>
<s>
Synthesia	B-Application
was	O
started	O
around	O
2006	O
by	O
Nicholas	O
Piegdon	O
,	O
and	O
was	O
originally	O
named	O
"	O
Piano	B-Application
Hero	I-Application
"	O
.	O
</s>
<s>
Hosted	O
as	O
an	O
open-source	B-License
project	O
on	O
SourceForge	B-Application
,	O
it	O
was	O
released	O
under	O
the	B-License
MIT	I-License
license	I-License
.	O
</s>
<s>
The	O
program	O
was	O
originally	O
for	O
Windows-only	O
,	O
but	O
after	O
a	O
donation	O
drive	O
in	O
early	O
2007	O
,	O
it	O
was	O
ported	O
to	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
.	O
</s>
<s>
An	O
open	B-License
source	I-License
fork	O
for	O
Linux	B-Application
called	O
Linthesia	O
also	O
exists	O
,	O
which	O
is	O
used	O
as	O
a	O
base	O
of	O
other	O
forks	O
to	O
fix	O
compilation	O
issues	O
on	O
recent	O
Linux	B-Application
systems	O
.	O
</s>
<s>
In	O
a	O
letter	O
dated	O
26	O
March	O
2007	O
,	O
Activision	O
requested	O
that	O
Piegdon	O
"	O
immediately	O
cease	O
any	O
and	O
all	O
use	O
of	O
the	O
"	O
Piano	B-Application
Hero	I-Application
"	O
name	O
in	O
connection	O
with	O
the	O
distribution	O
and	O
promotion	O
of	O
 [ his ] 	O
video	O
game	O
and	O
agree	O
not	O
to	O
use	O
such	O
in	O
the	O
future	O
"	O
.	O
</s>
<s>
Piegdon	O
responded	O
by	O
hosting	O
a	O
contest	O
for	O
a	O
new	O
name	O
for	O
the	O
project	O
,	O
resulting	O
in	O
the	O
name	O
,	O
Synthesia	B-Application
,	O
suggested	O
by	O
Daniel	O
Lawrence	O
.	O
</s>
<s>
However	O
the	O
last	O
open-source	B-License
release	O
version	O
0.6.1b	O
is	O
still	O
available	O
for	O
download	O
.	O
</s>
<s>
In	O
December	O
2014	O
,	O
with	O
Version	O
10	O
of	O
Synthesia	B-Application
,	O
the	O
ability	O
to	O
use	O
the	O
program	O
without	O
purchasing	O
it	O
was	O
removed	O
,	O
with	O
the	O
exception	O
of	O
several	O
playable	O
included	O
demo	O
MIDIs	O
.	O
</s>
<s>
Synthesia	B-Application
has	O
support	O
for	O
playing	O
custom	O
MIDI	O
and	O
MusicXML	O
files	O
,	O
as	O
well	O
as	O
linking	O
with	O
MIDI	O
controllers	O
.	O
</s>
<s>
Synthesia	B-Application
will	O
rate	O
the	O
player	O
's	O
performance	O
afterwards	O
,	O
and	O
give	O
a	O
score	O
which	O
can	O
be	O
submitted	O
to	O
an	O
online	O
scoreboard	O
.	O
</s>
<s>
Synthesia	B-Application
also	O
has	O
a	O
paid	O
"	O
Learning	O
Pack	O
"	O
that	O
allows	O
users	O
to	O
view	O
music	O
in	O
musical	O
notation	O
,	O
as	O
well	O
as	O
multiple	O
practice	O
features	O
,	O
such	O
as	O
"	O
Melody	O
Practice	O
"	O
which	O
pauses	O
the	O
piece	O
whenever	O
the	O
user	O
misses	O
a	O
note	O
,	O
and	O
only	O
continues	O
when	O
the	O
right	O
note	O
is	O
played	O
.	O
</s>
