In musical choral notation, TTBB denotes a four-part men's chorus. Its configuration is Tenor 1, Tenor 2, Bass 1 (Baritone), Bass 2.
The Tanunda Liedertafel 1861 employs this method of notation in their music.
Typically (but not always) the 1st Tenor part is the melody, with the other parts as harmony(s).
The Tanunda Liedertafel in parts are expressed as; 1st Tenor, 2nd Tenor, 1st Bass, 2nd Bass.
The way traditional German music notation is expressed (with two staves): T1 - treble clef 8va - up stem, T2 - treble clef 8va - down stem, B1 - bass clef - up stem, B2 - bass clef - down stem.
The above may not be true for some recently written (composed) music, however writers make it is easy to see which part sings their respective pitch. For example, T1 and B1 the highest pitch on each stave. Most of the time, this occurs where T1(B1) and T2(B3) are singing at the same time (in time).
Sometimes (rarely) the melody part (or lead) is sung as a solo, with the choir singing the harmony parts (support or backing vocals). (The recent rendition of The Holy City sung by the Liedertafel demonstrates this - though no audio recording of this exists)
There's war in the heavens
Rebellion on high
the son of the morning
Descends from a black sky
Severed and broken
His wings burned to dust
His coverings of diamonds and gold
In a moment in time dissolve to rust
Thunder and lightning
Shatter the night
The dragon of darkness
Appears cursed by the keeper of the light
The dark is chosen
The scroll has been sealed
Hidden in verses of prophets
His face is revealed
Songs of glory
Shout across the land
I can take you there
Child of mine, take my hand
Down through the ages
The story's been told
The daughter of wisdom
Beguiled by the serpent of old
Born into sin in a valley of thorns
Torn from enchantment and
Tossed into the eye of the storm
Heaven's garden
Made by God for man
This is paradise
Child of mine, take my hand
Glory to glory
Sin after sin
The rider of death
Pushes on to the place where
The battle must begin
Songs of glory
Shout across the land
This is paradise
Won't you take my hand
Heaven's garden
Made by God for man
This is paradise
Child of mine, take my hand
Oh, take my hand