This is a mixed vals tanda built around Osmar Maderna’s exquisite “Pequeña”. I picked Calo’s version of “Jugando, jugando” because it features Maderna as pianist and the sound of the orchestra is similar to Maderna’s. However, as DJ Mary Wu pointed out to me, Lomuto’s version of that tango (with Carlos Galarce, 1944) has a kind of bittersweet quality that is present in “Pequeña”, but absent in Calo’s version. So I suggest experimenting with both versions, as I have myself done over the past few weeks at various milongas. You may also want to try substituting ‘Una vez en la vida’ (Osvaldo Fresedo with Ricardo Ruiz, 1941) for ‘Motivo de vals’ if you find the tempo of the latter unacceptably slow (personally I find that it works at some milongas but not others, depending on the energy levels).
The discographies of the tango orchestras are scattered all around the web. Below is my best attempt to make the relevant links all available in one place. When I found more than one discography for a given orchestra, I chose the one which seemed most complete and reliable. I plan to keep this post updated, so if you think I’m missing something, please let me know.
Update: See here for my current attempt to improve on these discographies. The links below will gradually link to my own discographies, as they become available.