<s>
Leaf	B-Application
Trombone	I-Application
:	I-Application
World	I-Application
Stage	I-Application
was	O
a	O
massively	B-Application
multiplayer	I-Application
online	I-Application
music	B-Application
game	I-Application
for	O
the	O
Apple	B-Operating_System
iOS	I-Operating_System
,	O
developed	O
by	O
Smule	B-Application
and	O
released	O
on	O
April	O
15	O
,	O
2009	O
through	O
the	O
App	B-Application
Store	I-Application
.	O
</s>
<s>
In	O
the	O
game	O
,	O
players	O
can	O
play	O
the	O
Leaf	B-Application
trombone	I-Application
along	O
to	O
a	O
variety	O
of	O
tunes	O
,	O
as	O
well	O
as	O
compose	O
and	O
publish	O
songs	O
of	O
their	O
own	O
for	O
anyone	O
to	O
play	O
.	O
</s>
<s>
The	O
creators	O
at	O
Smule	B-Application
claim	O
that	O
Leaf	B-Application
Trombone	I-Application
:	I-Application
World	I-Application
Stage	I-Application
is	O
"	O
an	O
instrument	O
,	O
a	O
game	O
,	O
and	O
a	O
huge	O
global	O
social	O
experience.	O
"	O
</s>
<s>
The	O
Leaf	B-Application
trombone	I-Application
can	O
be	O
played	O
in	O
two	O
ways	O
.	O
</s>
<s>
The	O
user	O
must	O
first	O
decide	O
between	O
blowing	O
into	O
the	O
iPhone	O
microphone	O
(	O
or	O
a	O
peripheral	O
microphone	O
if	O
using	O
iPod	B-Device
Touch	I-Device
)	O
,	O
or	O
the	O
user	O
can	O
switch	O
on	O
"	O
Touch	O
mode	O
"	O
in	O
the	O
Settings	O
menu	O
,	O
which	O
allows	O
the	O
user	O
to	O
press	O
and	O
play	O
.	O
</s>
<s>
Once	O
a	O
song	O
has	O
been	O
selected	O
,	O
the	O
Leaf	B-Application
Trombone	I-Application
pops	O
up	O
.	O
</s>
<s>
Here	O
,	O
a	O
small	O
music	B-Application
wheel	O
plays	O
in	O
the	O
bottom	O
left	O
hand	O
corner	O
,	O
providing	O
background	O
accompaniment	O
and	O
guide	O
leaves	O
that	O
float	O
toward	O
the	O
leaf	B-Application
trombone	I-Application
as	O
the	O
song	O
progresses	O
,	O
showing	O
just	O
where	O
to	O
press	O
along	O
the	O
leaf	O
itself	O
and	O
how	O
long	O
to	O
hold	O
each	O
note	O
.	O
</s>
<s>
Free	O
Play	O
–	O
Selecting	O
free	O
play	O
provides	O
the	O
user	O
with	O
a	O
place	O
to	O
play	O
without	O
the	O
background	O
accompaniment	O
of	O
the	O
music	B-Application
box	O
and	O
the	O
help	O
of	O
guide	O
leaves	O
.	O
</s>
<s>
Along	O
the	O
right	O
side	O
of	O
the	O
screen	O
,	O
is	O
the	O
Leaf	B-Application
trombone	I-Application
itself	O
with	O
an	O
overlapping	O
indicator	O
for	O
where	O
one	O
's	O
finger	O
is	O
currently	O
sitting	O
on	O
the	O
instrument	O
.	O
</s>
<s>
Eight	O
small	O
notches	O
exist	O
along	O
the	O
length	O
of	O
the	O
Leaf	B-Application
Trombone	I-Application
indicating	O
the	O
eight	O
notes	O
on	O
a	O
major	O
scale	O
.	O
</s>
<s>
Leaf	B-Application
Trombone	I-Application
:	I-Application
World	I-Application
Stage	I-Application
was	O
first	O
demonstrated	O
at	O
Apple	O
's	O
iPhone	B-Operating_System
OS	I-Operating_System
3.0	O
keynote	O
on	O
March	O
17	O
,	O
2009	O
.	O
</s>
<s>
Co-Founder	O
,	O
CTO	O
,	O
and	O
Chief	O
Creative	O
Officer	O
of	O
Smule	B-Application
,	O
Ge	O
Wang	O
presented	O
the	O
application	O
in	O
the	O
form	O
of	O
a	O
duet	O
with	O
another	O
co-worker	O
.	O
</s>
<s>
Since	O
the	O
games	O
general	O
release	O
on	O
April	O
15	O
,	O
2009	O
,	O
it	O
has	O
been	O
received	O
well	O
,	O
earning	O
high	O
marks	O
within	O
the	O
Apple	B-Application
App	I-Application
Store	I-Application
( +	O
4/5	O
)	O
,	O
and	O
receiving	O
critical	O
acclaim	O
from	O
sites	O
such	O
as	O
iLounge	O
,	O
PC	O
World	O
,	O
and	O
TechCrunch	O
.	O
</s>
