What is the difference between Nevel and Kinor?
Rashi: Nevel has more strings than Kinor. It is called Nevel, because it is Menavel (debases) all other instruments (Shocher Tov 81:3).
What is "Toref"?
Rashi: It is a [drum] of skin.
What is "Chalil"?
Rashi: It is a flute.
Why does it mention all these instruments?
Radak: They played them at their drinking parties; this drew them to drink [more].
Why does it say "v'Es Po'al Hashem Lo Yabitu"?
Rashi citing Targum Yonasan: They do not look at Hashem's Torah.
Radak #1: They were idle from work, for they were rich. Their entire engagement is to drink and hear songs. They do not engage in Torah and Divrei Chachamim, which are "Po'al Hashem."
Radak #2: "Po'al Hashem" and "Ma'ase Yadav" is astronomy. From it, man understands honor of the Creator - "Mah Adir Shimcha b'Chol ha'Aretz", "Ki Er'eh Shamecha Ma'ase Eztbe'osecha", (Tehilim 8:2, 4), "ha'Shamayim Mesaperim Kevod Kel" (ibid., 19:2). One who understands the secret of their creation, knows Hashem's honor. "Se'u Marom Eineichem u'Re'u Mi Vara Eleh" (below, 40:26). 'One who knows how to calculate Tekufos and Mazalos, and does not "v'Es Po'al Hashem Lo Yabitu u'Ma'ase Yadav Lo Ra'u" applies to him. Also refer to 5:12:6:2.
Malbim: They do not investigate Hashem's conduct and Hashgachah.
Why does it say "u'Ma'ase Yadav Lo Ra'u"?
Rashi #1: They pretended not to see His Gevuros (mighty acts).
Rashi #2 (from Shabbos 119b): They did not praise Him with 'Yotzer Ohr' in the morning and not 'ha'Ma'ariv Aravim' at night (the first Brachah before Keri'as Shma). 1
Radak: "Ma'ase Yadav" are the Aseres ha'Dibros on the Luchos; they are the Klal for all the Mitzvos Bein Adam l'Chavero and Bein Adam la'Makom.
Malbim: They never saw His acts - how will they pay attention now, at their wine party?
The Gemara says that they neglected Keri'as Shma in the morning and at night. Perhaps Rashi infers that all the more so they neglected the Brachos of Shma, which discuss His Ma'asim. However, perhaps they said Shma and its Brachos, but did not fulfill Keri'as Shma because they did not accept Ol Malchus Shamayim, or it was not the proper time (after three hours in the morning, or before Tzeis ha'Kochavim at night)! (PF)
