Mariela Castro, director of the Cuban National Center for Sex Education and daughter of the president, slammed Carcasses' comments on Thursday as "opportunistic."
"He can say whatever he wants .... he is free to speak his mind, however superficial what he is saying may be," she said curtly.
Carcasses, a pianist and leader of the musical organization "Interactivo," called for greater political freedoms, including the right to vote directly for the Cuban president, while singing at a concert advocating the release of four Cuban agents convicted of espionage in the US.
The musician later said he was called in for a meeting with a Culture Ministry official after the improvised message at Thursday evening's benefit concert.
The official told him he "would be banned indefinitely from all institutions governed by the agency," Carcasses, 41, wrote on Interactivo's Facebook page.
Currently, Cubans do not vote directly for their leaders. They vote in neighborhood assemblies for people to take part in Communist party assemblies, and then those assemblies elect assemblies above them, including national leaders for the country of 11 million.
At the concert, Carcasses changed the lyrics of a song, demanding free access to information, an end to US economic and political sanctions on Havana, and an end to Cuba cutting itself off from outside influence.
He also called for a country that does not distinguish between "militants and dissidents," meaning Communist party faithful and all others.
The outdoor event, which included performances by 30 artists, was attended by thousands of people.
Thanks to the loud music and poor sound quality, few concertgoers were apparently immediately able to make out Carcasses's bold political challenges.
But his message gained traction this week on social networks, and Cubans have voiced a range of opinions on the matter.
Digna Guerra, director of the National Choir of Cuba, was "outraged" at the incident, which she called "unacceptable."
"One must have the ethics and responsibility to raise our standards at the right place and time," Guerra said on the Culture Ministry's news portal.
Likewise, legendary folk singer Silvio Rodriguez said on his blog Carcasses "made a great blunder." But Rodriguez wrote he would still "invite the sanctioned musician to my upcoming concerts, because one mistake should not breed another."
However, Carcasses found support in other quarters.
Puerto Rican musician Eduardo Cabra who is married to Cuban singer Diana Fuentes and is a member of the Grammy-winning international band "Calle 13" called for lifting Carcasses' banishment entirely.
"An important voice in Latin America should not be silenced, and there should not be censorship of thought and expression, so that Cuba can show the world its Revolution has deep roots," Cabra wrote in an online posting.
Carcasses said the officer who notified him of his punishment told him "with great respect, that these statements were not in line with the Cuban Revolution, and that this was not the place for that."
"I do not see why my ideas do not conform with the Cuban Revolution, if we are trying to improve our system," he said.
"I am convinced that in reality what would have been opportunistic would have been to stand on the stage at a political-cultural event convened by the government and be in absolute agreement, when those were not my true feelings," he said.
"Maybe I was wrong to expect my words to inspire tolerance and evolution of the Cuban government," he said.