This is orchestra Fresedo with singer Ricardo Ruiz. Fresedo was a bandoneonist. His family was rich (his father was a businessman). The tangos with Ruiz are from late 30s and early 40s, I think, but Fresedo was already successful much earlier, in the 20s. Even before that he played with Firpo and Canaro, and also recorded with Gardel in the 20s. Towards the end of the 20s he already had 5 orchestras or so. He was super successful.
His style: romantic, posh, also including unconventional instruments. Whenever you hear harp, for instance, it's Fresedo, so it's easy to recognize. Sometimes he also uses drums and vibraphones. His singers: sweet voices. Ray and Ruiz are the most famous. In style he influences di Sarli a lot. Di Sarli was actually leading one of Fresedo's 5 orchestras, that's probably partly why.
Finally, Fresedo also composed pieces like 'Vida mia' and 'Sollozos' (both with Ray, another day).
http://www.youtube.com/watch?v=CajwRRew_Dk
http://www.youtube.com/watch?v=qrhvPsQU1dQ
http://www.youtube.com/watch?v=SOWS6_bFUlY