Impairments in attention are commonly seen in individuals with traumatic brain injury (TBI). While attention assessment measurements have been developed rigorously and utilized frequently in cognitive neurorehabilitation, there is a paucity of auditory attention assessment instruments that are ecologically valid and that assess different subtypes of attention. Yet, deficits in auditory attention can severely limit everyday functioning, negatively impact work and personal relationships and compromise personal safety. The purpose of this study was to develop and to investigate the psychometric properties of a Music-based Attention Assessment (MAA) instrument. The MAA is a multiple choice, melodic contour identification test, designed to assess three different types of auditory attention, including sustained attention, selective attention, and divided attention. The MAA was piloted with patients with TBI ( n = 15) and healthy adults (n = 30) separately to evaluate preliminary psychometric properties. Both pilot studies reported that the MAA possessed a very high reliability and appropriate item properties. However, the MAA was revised due to a ceiling effect on mean test scores in the healthy adult group. The revised version of the MAA was administered to healthy adults (n = 165) as well as TBI patients ( n = 22) to investigate construct validity, item properties, test reliability, and difference in MAA performance between groups. Here, psychometric validation of the revised version of the MAA is described, and the obtained results reported. Exploratory factor analysis identified five-factor constructs, supporting the different types of attention that underlie the test items of the revised version of the MAA. The factors identified were Sustained-Short, Sustained-Med to Long, Selective-Noise, Selective & Divided, and Divided-Long. After item elimination, the finalized 45-item MAA in relation to the identified five-factor constructs provided evidence of high internal consistencies as computed by split-half reliability coefficients (r = .836) and Cronbach's alpha (&agr; = .940), indicating homogeneity of test items within each of the five subtest as well as for the total test. As predicted, significant differences were found between the healthy adult and TBI patient samples across the exploratively obtained five-factor constructs of the revised version of the MAA. The MAA performance was significantly better in the healthy adult group than in the TBI patient group, except on the Sustained Attention-Short Subtest, indicating pervasive attention impairments in patients with TBI. The finding also suggests that a basic level of sustained attention to deal with a small amount of auditory information during a limited time might be intact for the patients with TBI who have a moderate to severe level of brain injury. The aggregate findings suggest that the MAA is a valid and reliable measure that provides diagnostic information in regards to the three types of auditory attention deficits frequently observed in patients with TBI. The use of melodic contours in attention assessment is discussed along with limitations of the study and suggestions for future research. The MAA, when used in conjunction with attention assessment instruments in different sensory modalities, would provide a greater level of precision in the attention assessment of patients with TBI, resulting in more symptom specific and individualized rehabilitation and treatment.