Can you use the song “All Things Are Ready” to introduce the Lord’s Supper?

Answer:

"All things are ready,” come to the feast!
Come for the table now is spread;
Ye famishing, ye weary, come,
And thou shalt be richly fed.

“All things are ready,” come to the feast!
Come, for the door is open wide;
A place of honor is reserved
For you at the Master’s side.

“All things are ready,” come to the feast!
Come, while He waits to welcome thee;
Delay not while this day is thine,
Tomorrow may never be.

“All things are ready,” come to the feast!
Leave every care and worldly strife;
Come, feast upon the Christ of God
And drink everlasting life.

Chorus:
Hear the invitation,
Come, whosoever will;
Praise God for full salvation
For whosoever will.

by Charles Hutchinson Gabriel

The song is based on Jesus' parable of the wedding feast:

"The kingdom of heaven may be compared to a king who gave a wedding feast for his son. And he sent out his slaves to call those who had been invited to the wedding feast, and they were unwilling to come. Again he sent out other slaves saying, 'Tell those who have been invited, "Behold, I have prepared my dinner; my oxen and my fattened livestock are all butchered and everything is ready; come to the wedding feast."' But they paid no attention and went their way, one to his own farm, another to his business, and the rest seized his slaves and mistreated them and killed them. But the king was enraged, and he sent his armies and destroyed those murderers and set their city on fire. Then he *said to his slaves, 'The wedding is ready, but those who were invited were not worthy. Go therefore to the main highways, and as many as you find there, invite to the wedding feast.' Those slaves went out into the streets and gathered together all they found, both evil and good; and the wedding hall was filled with dinner guests. But when the king came in to look over the dinner guests, he saw a man there who was not dressed in wedding clothes, and he said to him, 'Friend, how did you come in here without wedding clothes?' And the man was speechless. Then the king said to the servants, 'Bind him hand and foot, and throw him into the outer darkness; in that place there will be weeping and gnashing of teeth.' For many are called, but few are chosen" (Matthew 22:2-14).

The parable and the song describe God's invitation for people to become part of His church. The word translated as "dinner" actually refers to a morning meal in Greek, a "brunch" in modern English terminology. It is the meal that traditionally started off a wedding ceremony. The "feast" does not refer to the Lord's Supper, but to the opportunity to have fellowship with God and His people. A feast of spiritual blessings is available in the church, the greatest of which is salvation from our sins.

The marriage between Christ and his bride (the church) has not yet taken place. That happens after the world ends at the Lord's second coming (Revelation 21:1-2). But in preparation for the wedding, the guests are invited to start celebrating what will eventually take place.

There are no prescribed songs to be sung before the Lord's Supper. However, if the intention is to lead a song that helps people think about the crucifixion, then this song would not fit. It is a song inviting people to become Christians.