Roman architecture continued the legacy left by the earlier architects of the Greek world, and the Roman respect for this tradition and their particular reverence for the established architectural orders, especially the Corinthian, is evident in many of their large public buildings. However, the Romans were also great innovators and they quickly adopted new construction techniques, used new materials, and uniquely combined existing techniques with creative design to produce a whole range of new architectural structures such as the basilica, triumphal arch, monumental aqueduct, amphitheater, granary building, and residential housing block. Many of these innovations were a response to the changing practical needs of Roman society, and these projects were all backed by a state apparatus which funded, organized, and spread them around the Roman world, guaranteeing their permanence so that many of these great edifices survive to the present day.
I think they adopted Corinthian order, for this type of orders can be seen on many cathedrals around Europe including those in France, Malta (Valletta), etc.
Many scales are diatonic including Major, Minor (the Harmonic minor is an exception) and modal scales. Examples of non-diatonic scale are pentatonic, octatonic and whole-tone scales.
