If you need to copy and paste... ;-)
accordion
acoustic_bass
acoustic_grand_piano
acoustic_guitar_nylon
acoustic_guitar_steel
agogo
alto_sax
applause
bagpipe
banjo
baritone_sax
bassoon
bird_tweet
blown_bottle
brass_section
breath_noise
bright_acoustic_piano
celesta
cello
choir_aahs
church_organ
clarinet
clavinet
contrabass
distortion_guitar
drawbar_organ
dulcimer
electric_bass_finger
electric_bass_pick
electric_grand_piano
electric_guitar_clean
electric_guitar_jazz
electric_guitar_muted
electric_piano_1
electric_piano_2
english_horn
fiddle
flute
french_horn
fretless_bass
fx_1_rain
fx_2_soundtrack
fx_3_crystal
fx_4_atmosphere
fx_5_brightness
fx_6_goblins
fx_7_echoes
fx_8_scifi
glockenspiel
guitar_fret_noise
guitar_harmonics
gunshot
harmonica
harpsichord
helicopter
honkytonk_piano
kalimba
koto
lead_1_square
lead_2_sawtooth
lead_3_calliope
lead_4_chiff
lead_5_charang
lead_6_voice
lead_7_fifths
lead_8_bass__lead
marimba
melodic_tom
music_box
muted_trumpet
oboe
ocarina
orchestra_hit
orchestral_harp
overdriven_guitar
pad_1_new_age
pad_2_warm
pad_3_polysynth
pad_4_choir
pad_5_bowed
pad_6_metallic
pad_7_halo
pad_8_sweep
pan_flute
percussive_organ
piccolo
pizzicato_strings
recorder
reed_organ
reverse_cymbal
rock_organ
seashore
shakuhachi
shamisen
shanai
sitar
slap_bass_1
slap_bass_2
soprano_sax
steel_drums
string_ensemble_1
string_ensemble_2
synth_bass_1
synth_bass_2
synth_brass_1
synth_brass_2
synth_choir
synth_drum
synth_strings_1
synth_strings_2
taiko_drum
tango_accordion
telephone_ring
tenor_sax
timpani
tinkle_bell
tremolo_strings
trombone
trumpet
tuba
tubular_bells
vibraphone
viola
violin
voice_oohs
whistle
woodblock
xylophone