No, the original 1988 film The Land Before Time is not a musical.
The Land Before Time (1988)
Based on the provided information, the inaugural film in the long-running series, released in 1988, stands apart from its numerous sequels in several ways. One significant distinction highlighted is its lack of musical numbers.
According to the reference, the first film is specifically noted as "the only film in The Land Before Time series that is not a musical". This piece of information directly answers the question, indicating that while the franchise expanded with many subsequent films that incorporated songs and musical elements, the original theatrical release does not fall into the musical genre.
This characteristic is presented as a unique trait of the first movie, alongside other facts such as its theatrical worldwide release and the absence of Dom DeLuise, contrasting it with the rest of the series and other Don Bluth films from the same decade.
Therefore, if you are referring to the classic 1988 animated movie, it is not considered a musical film.