You can find a YouTube playlist here with many of the songs suggested below.
Gathering
The theme of creation praising God in the Old Testament would be a great place to begin and Joy to the world (CH 320 / MP 393) would link well with it also speaking of preparation which is a key theme in other readings and there are alternative versions from Chris Tomlin (CCLI) and Hillsong (CCLI). Other songs to consider in a range of different styles include From all that dwell below the skies (CH 146), Let all creation dance (CH 149), Earth, earth, awake; your praises sing (CH 420), Let all creation sing (Resound) and From life’s beginning / Let praise resound (Resound).
If you are using an Advent candle lighting song then Christmas is coming (CH 282 / CP 34) and Advent candles tell their story (STF 165 / link) are good options for the pattern of Hope, the Prophets, John the Baptist, and the Virgin Mary, while Hope is a candle, once lit by the prophets (CH 284) and We are a people of hope (Hope) work well for the Hope, Peace, Love, Joy themes.
Word
You might like to use a short Advent song before the reading of scripture. This is a good opportunity to give some musical continuity to the season, either by using the same song each week or by using songs in a similar style. The following songs all have a similar text, praying for Jesus to come, but use a mix of English, Latin and Aramaic: Maranatha (MV 19), Come, come Emmanuel (link), Veni, veni (WGRG), and Veni Immanuel (WGRG). There are also some settings of plainchant which can work well here as continuity through the season, with the simplicity of the music allowing an opportunity for the power of the words to really sink in. The Advent Prose (NEH 501) is widely sung throughout Advent while O heavenly Word of God on high (NEH 2) would be another option.
The most famous version of Psalm 146 is probably Isaac Watts’ I’ll praise my maker while I’ve breath (PFAS 146A / Hymnary) while Come praise the Lord with all our lives (Grace) is a good alternative metrical option. Put not your hope in the nation (Kimbrough) would be great for bands while the Psalm Project from the Netherlands have two versions of this psalm, I will sing out and Praise the Lord with joyful noises (sheet music in English / recording in Dutch). I will praise the Lord (GIA) is a good responsorial option and you could have a soloist or choir sing the verses or just use the refrain itself and have the verses spoken.
Response
Some of the songs suggested last week to link to John the Baptist could also work this week such as On Jordan's bank, the Baptist's cry (CH 334 / MP 538), Lo, in the wilderness a voice (NEH 170) and Through the prophets (New Scottish). You could also look at songs which focus more on the coming of Jesus and what that will mean for the world such as Hark the glad sound! the Saviour comes (CH 277 / MP 210), The voice of God goes out to all the world (CH 283) and If Jesus is come (GIA).
Songs about waiting would link well to the Epistle with the short chant Wait for the Lord (CH 276) and There is a longing in our hearts (CH 720) both also tying into themes from some of the other readings. Still, my soul, be still (CCLI / Townend) is a beautiful song to consider which is probably more suited to a solo singer but can work with congregation while Waiting here for you (CCLI) and Everlasting God / Strength will rise (CCLI) are good options for band.
As suggested last week, Isaiah the prophet has written of old (CH 241) is a lively song which links strongly to the Old Testament passage. The desert shall rejoice (Hope) and When the King shall come again (Jubilate) are both based on this passage, with the latter sung to either Ave Virgo Virginum or Tempus Adest Floridum (e.g.) Good King Wenceslas. Praise the One who breaks the darkness (CH 348) also picks up some of the themes, particularly in v2
Sending
The voice of God goes out to all the world (CH 283) would be a great closing song as it picks up themes from the readings and speaks of the transformation we are waiting on while the South African song Freedom is coming (WGRG), Make way, make way for Christ the King (CH 279 / MP 457) or the worship song Kingdom coming (CCLI) could also speak into that theme. You shall go out with joy (CH 804) would link to Isaiah and all of creation singing in praise to God. You can also consider general Advent songs such as People, look East. The time is near (CH 281) or Lift up your heads, eternal gates (CH 289).