1)
What are "Hamon Shirecha"?
1.
Rashi: The Leviyim, who sing on the Duchan, since you extort and make Mishpat crooked (I do not desire their Shirah). Radak - the Leviyim sang vocally and with instruments over the Korban. I do not desire the Korbanos, and not the Shirah. What do Korbanos help if you serve Me on one side, and rebel against Me on the other side?!
2.
Malbim: This refers to Shirah during the Chag, when they offer the Korban. They are not Shirei Hashem, rather, mere cacophony.
2)
What is "Zimras Nevalecha"?
1.
Malbim: It is Shirah with instruments (lyres).