What is Barbershop singing today? - (a general view point)
Barbershop is a style of unaccompanied singing for four voice parts. Unlike other forms of "a cappella" the harmony parts surround the melody line, or LEAD as we call it.
So, beyond the LEAD with the tune what do we have? Barbershop consists of a low BASS part, that is nearly always below the melody line. A high TENOR part which is nearly always above the melody line. The remaining part is BARITONE and that part can be above or below the LEAD part depending on what note is required to complete the chord. As such the BARITONE oftens ends up with the "musical scraps" - whatever is left after everyone else has got their note.
Barbershop singing is normally sung in single voice – all men or all women.
The barbershop style is also a visual performance, and unlike traditional choristers hiding behind their music scores, we stand and sing without written music and, more like musical theatre, try to bring a song to life.
Technically, Barbershop arrangements have a particular vocabulary of musical chords that must be used to be the kind of song we can sing in a Barbershop contest. That is mainly for the technical folk, but if you are interested in reading more about it follow this link.