OUTLINE: Randomized study. Patients without prior surgery are randomized 1:2 to Arms I:II-IV, while those with prior surgery are randomized 1:1 between Arms I and II only. Patients with tumors of the oral cavity or oropharynx may elect additional randomization between Arms V and VI and will receive irradiation of the primary according to the Manchester regimen. Arm I: Radiotherapy. Irradiation of the primary and/or lymph nodes according to 1 of 2 regimens (Manchester 3-week schedule or SECOG 6-week schedule) using megavoltage equipment. Arm II: Radiotherapy plus Concurrent Single-agent or 4-Drug Combination Chemotherapy with Leucovorin Rescue. Involved-field irradiation as in Arm I; plus Methotrexate, MTX, NSC-740; with Leucovorin calcium, CF, NSC-3590; or VBMF: Vincristine, VCR, NSC-67574; Bleomycin, BLEO, NSC-125066; MTX; Fluorouracil, 5-FU, NSC-19893; with CF. Arm III: Radiotherapy plus Subsequent Single-agent or 4-Drug Combination Chemotherapy with Leucovorin Rescue. Involved-field irradiation as in Arm I; plus MTX or VBMF; with CF. Arm IV: Radiotherapy plus Concurrent and Subsequent Single-agent or 4-Drug Combination Chemotherapy with Leucovorin Rescue. Involved-field irradiation as in Arm I; plus MTX or VBMF; with CF. Arm V: Radiotherapy. Neck node irradiation using megavoltage equipment. Arm VI: Observation. No nodal irradiation.