Contemporary reviews Contemporary reviews of
If You Can Believe Your Eyes and Ears were highly positive and frequently emphasized the Mamas & the Papas' vocal blend and harmonic style.
Record Mirror called the album "very sweet", noting its "clever harmonising" and describing it as "good listening". The
Journal & Courier's Angelyn Rizzo wrote that their sound featured "marvelous harmony" along with "unusual contrapuntal harmonies and unique individual vocal arrangements" that "make the album an entire pleasantry". Norman Barry of the
Sunday Independent argued that the album demonstrated the group's "versatility, originality, harmony and above all, their willingness to experiment and create". Bill Hilton of the
Santa Barbara News-Press expressed surprise at liking a
folk rock–based record but described the album as "good to listen to", praising the group's "uncommon blend of voices" and writing that they "harmonize beautifully" without being overshadowed by instrumentation.
The Daily Telegraph's Anne McDonald called the album "brilliant" and said their "voices that blend so perfectly" and orchestral backing "create a feeling of spine-tingling nostalgia". Ernie Santosuosso of
The Boston Globe wrote that the group "can do no wrong with a song" and compared their role in folk-rock to
the Four Freshmen's position in
jazz vocal music. He highlighted their "meticulous sounds and feeling for harmonics" and described the album as containing "refreshingly creative choral magic". Looking back at
If You Can Believe Your Eyes and Ears a year later, critics regarded it as their defining work for the Mamas & the Papas and emphasized its importance.
Robert Christgau called the album "a classical record with a new approach", and
Paul Krassner commented that the group "feel good to hear".
Richard Goldstein stated that the album "has the strongest composition on it" and argued that it "influenced the way other performers use harmony", while also noting that later records were "really only remakes of this first unique album".
Robert Fulford likewise described it as the album that "defines them". The
Star Weekly wrote that the "crystal voices" of the group were heard at their best on the debut and added that its songs "would make the album a significant contribution to the
pop-rock scene if they never cut another".
Retrospective reviews The album received a positive retrospective review in
Rolling Stone, in which critic
Rob Sheffield remarked "The Mamas and the Papas celebrated all the sin and sleaze of Sixties L.A. with folksy harmonies, acoustic guitars, and songs that told inquiring minds way more than they wanted to know. And on their January 1966 debut,
If You Can Believe Your Eyes and Ears, they somehow made it all sound groovy." He described the album as a dark look at L.A. culture that sounds accessible and optimistic thanks in large part to
Lou Adler's production. ==Track listing==