awalt:
There was a second reading at our Church on Ash Wednesday this week. It’s in the Magnificat also.
Yes, Wednesday was Ash Wednesday, a solemnity. Therefore following the 2002 General Instruction of the Roman Missal (GIRM) 357: “For Sundays and solemnities, three readings are assigned: that is, from a Prophet, an Apostle, and a Gosepl …”.
Perhaps the Conference of Bishops has the power to change this. From the 1981 General Introductiont to the Lectionary for Mass, n. 79 “If, however, for pastoral reasons the conference of bishops has permitted use of only two readings …”.
This is also indicated in the 2002 GIRM 362. The approved translation for England and Wales has: “362. In addition to the faculty of choosing certain more suitable texts, as noted above the Conference of Bishops has the faculty, in special circumstances, to make further adaptations of readings, provided that the texts are to be taken from a duly approved Lectionary.”
Another possibility is that it was a Mass for Children. According to the 1973 Directory for Masses with Children: “42. With regard to the number of readings on Sundays and feast days, the decrees of the conference of bishops are to be observed. If three or even two readings appointed on Sundays or weekdays can be understood by the children only with difficulty, it is permissible to read two or only one of them, but the gospel reading should never be omitted.”