The baglama and the tzouras are small, long-necked lutes derived from the bouzouki. The three instruments make up the typical ensemble associated with rebetiko music and songs.
The tzouras is very similar to the bouzouki. Their main difference lies in their size. Both the soundbox and the neck are smaller and that accounts for the deeper sound that the instrument gives. It is also tuned in D-A-D, although the even shorter tzouras is tuned in G-D-G.
The baglamas is the smallest instrument in this group. It has three double-course strings and is tuned an octave higher than the bouzouki. It originated at a time when the rebetes were persecuted by the authorities and their instruments and music were forbidden. It is known as the bouzouki of the prison, where the rebetes started making bouzoukia small enough, so that they could easily be concealed in the cells.