what prayer that can be playable on altar that can be play 24/7 catholic teaching

In a Catholic context, the playing of recorded prayers or music on an altar continuously (24/7) is generally not part of official liturgical practice. The Church emphasizes prayer as a conscious human action and living relationship with God, and recorded media cannot substitute for the personal, active participation of the faithful.

However, the practice of continuous, private prayer by individuals is highly encouraged, especially in the context of Eucharistic Adoration. In a chapel dedicated to perpetual adoration, the Blessed Sacrament is exposed, and volunteer parishioners commit to praying in its presence for a specific period (usually an hour or more), ensuring someone is always present, day and night.

During these private times of prayer, individuals can silently or audibly recite a variety of traditional Catholic prayers.

Suitable Catholic Prayers for Private Continuous Devotion

If you are looking for prayers to use during personal, continuous devotion (which might be the intent behind a 24/7 "playable" prayer), the following are common and appropriate:

The Rosary: This is perhaps the most well-known Catholic daily prayer tradition, consisting of a series of prayers (the Our Father, Hail Mary, and Glory Be) and meditations on the life of Christ and the Virgin Mary.

The Chaplet of Divine Mercy: A set of prayers typically recited using Rosary beads, focusing on God's mercy.

Basic Daily Prayers: These include foundational prayers of the Catholic faith:

The Our Father (The Lord's Prayer)

The Hail Mary

The Glory Be

The Act of Contrition

The Morning Offering

Litanies: The Litany of Mary (Salve Regina, or "Hail, Holy Queen") and the Prayer to St. Michael the Archangel are often used.

Contemplative Prayer: During perpetual adoration, many people simply sit in silent contemplation and enjoy the Lord's presence, sometimes reading the Bible or spiritual books.

Official Teaching on Recorded Prayer

The Church generally prohibits the use of recorded music or prayers during formal liturgical celebrations (like Mass), as liturgy involves the conscious, active participation of the gathered assembly. Prayer and worship must come from the hearts of the people, not from a machine.

However, in private spaces or for personal devotion outside of official liturgy, the use of audio aids is generally a matter of personal discretion, provided they foster a spirit of authentic prayer and reverence. The key is that the audio should be an aid to personal prayer, not a replacement for it.