I don't know ABCExplorer but abc can use multiple voices. Here is a shortened (2 of 4 parts shown) example from Joe's folkinfo songs:

[pre]X:1    %Music
T:Diadem
B:Ian Russell,A Festival of Carols - A Second Collection of Carols from the Mount-Dawson Manuscripts, Sheffield, 1996
C: Arr. Ian Russell, http://www.sgpublishing.co.uk/gm/vc/vcabout.html
Z:Ian Russell
Q:1/4=112    %Tempo
V:1 clef=treble name="Soprano"
M:3/4    %Meter
L:1/8    %
K:G
D2 |G4 A2 |(B3/2c/d2) G2 |A2 G2 F2 |
w:All hail the power__ of Je-*sus'
G4 (FE) |D3 E DC |(B,2D2) G2 |(E2c2) c2 |
w:name, Let_ an-gels prost-rate fall_ Let an-*gels
B4 A2 |G6-|G4 (GA) |B4 B2 |
w:prost-rate fall *Bring_ forth the
B2 A2 G2 |A2 G2 F2 |G3/2A/ B2 d2 |(c3BAc|
w:roy-*al di-*a-dem__ And crown___
B3AGB|A3GFA|G2) G2 z2 |c2 c2 z2 |
w:_________ Him, crown Him,
A2 A2 z2 |B2 B2 d2 |(G3/2A/B2) A2 |G4 F2 |G6-|G4 z2 |]
w:crown Him, crown Him, And crown__ Him Lord of all!
V:2 clef=treble name="Alto"
M:3/4    %Meter
L:1/8    %
K:G
B,2 |D4 D2 |D4 D2 |E2 D2 D2 |
D4 (DC) |B,3 C B,A, |(G,2B,2) D2 |E4 E2 |
D4 DC |B,6-|B,4 D2 |D4 D2 |
D2 C2 B,2 |E2 D2 D2 |D4 D2 |E2 E2 z2 |
w:******* And crown Him, *
D2 D2 z2 |D2 D2 z2 |D2 D2 z2 |(E3DCB,|
w:crown Him. crown Him, crown Him crown___
D6-|D2 D2 D2 |D4 C2 |D4 D2 |D6-|D4 z2 |]
w: __ Him, And crown Him Lord of all! [/pre]