1)
How will they praise Him?
1.
Radak: Verbally, and with instruments.
2.
Malbim: When they will dance in a circle, and play in front of Him with drums and harps (people commonly sing at the time - "va'Tetzenah Kol ha'Nashim Achareha b'Supim uvi'Mcholos" - Shemos 15:20). In the future, Hashem will make a dance for Tzadikim. They will surround Him (Ta'anis 31a), and be His close nation.
