You can find a YouTube playlist here with many of the songs suggested below.
Gathering
The psalm is a strong gathering text today, with God summoning the earth, calling to the heavens, and shining in perfect beauty and a setting of it such as God the Lord, the King almighty (CH 39) could work well as an opening hymn. Other songs which pick up on these themes include Jesus shall reign where’er the sun (CH 470 / MP 379) and it’s alternative version with added chorus - Jesus shall reign (CCLI / Getty), Bright morning maker as your sun breaks through (CCLI) (sung to Engelberg or Sine Nomine), Creation sings the Father's song (MP 1268 / CCLI) and Heaven’s voice brings the dawn (Resound).
Word
There are relatively few settings of Psalm 50 but if you didn’t use God the Lord, the King almighty (CH 39) as an opening hymn then it is worth considering. Other metrical settings you could use are The mighty God with power speaks (PFAS 50A / Hope) sung to Kingsfold and The Lord of the ages, the Father of years (CCLI) vv.1-3 which could be sung to Slane. Let the giving of thanks (WGRG) can either be sung in full with the chorus and verses, or else the chorus could be used to sing the psalm responsorially.
Response
Today’s Gospel is in two parts. The first is the end of the Parable of the Rich Fool and could link to songs about living simply and following Jesus’ way such as Will you come and follow me (CH 533), Lord, you have come to the seashore (CH 532) and Simple living (MP 1251 / CCLI / Townend), Where your treasure is (GIA) is based on v34 with a simple chorus while a soloist or choir can sing the verses. The second part focuses on being ready for Christ’s coming and you could use the Taizé chant Wait for the Lord (CH 276) or Christ be our light (CH 543 / MP 1201). Word of the Father (CH 480) is a beautiful short song which could bring both parts together as a prayer for Christ to come and to take our fear away
By faith (MP 1262 / CCLI / Getty) ties strongly into the Epistle, both thematically and with its use of the same repeated phrase. Promises (CCLI) and To Abraham and Sarah (Hymnary / link) sung to Thornbury are songs which would pick up the focus on Abraham and those who follow him. You could also use some classic hymns which pick up themes of the journey of faith and of the city God has prepared such as Guide me, O thou great Jehovah (CH 167 / MP 201), Glorious things of thee are spoken (CH 738 / MP 173) and Who would true valour see (CH 535 / MP 224).
The call in the Old Testament to “do good, seek justice” etc. in v17 can link us to a range of songs on the theme of justice including songs from around the world such as For the world and all its people (CH 262) which links together worship and justice, When the hungry who have nothing (CH 258), and El mensaje que hoy proclamamos / Hear the message we now are proclaiming (H 46) and worship songs such as God of all comfort (Resound), God of justice (MP 1174 / CCLI) and Act justly, love mercy, walk humbly (CCLI).
Sending
The call to justice is a good sending theme which can also link to the urgency of Christ’s coming again in songs such as Sent by the Lord am I (CH 250), Canticle of the turning (Wild Goose / PFAS 75B / MV 120) and Beauty for brokenness / God of the poor (CH 259 / MP 806). There are also various songs suggested above for particular passages which work well as sending songs including Christ be our light (CH 543 / MP 1201), Guide me, O thou great Jehovah (CH 167 / MP 201) and God of justice (MP 1174 / CCLI).